UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

(Mark One)



x	QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended March 31, ~~2018~~2019



¨	TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

~~Commission File Number: 001-3280~~

~~Public Service Company of Colorado~~

~~(Exact name of registrant as specified in its charter)~~



~~Colorado~~001-03280		84-0296600
(~~State or other jurisdiction of incorporation or organization)~~Commission File Number)		(I.R.S. Employer Identification No.)



(Registrant, State of Incorporation or Organization, Address of Principal Executive Officers and Telephone Number)
Public Service Company of Colorado
(a Colorado corporation)
1800 Larimer, Suite 1100
Denver, ~~Colorado~~		CO 80202
~~(Address of principal executive offices)~~		~~(Zip Code)~~303-571-7511

~~(303) 571-7511~~

~~(Registrant’s telephone number, including area code)~~

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. x Yes ¨ No

Indicate by check mark whether the registrant has submitted electronically ~~and posted on its corporate Web site, if any,~~ every Interactive Data File required to be submitted ~~and posted~~ pursuant to Rule 405 and Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit ~~and post~~ such files). x Yes ¨ No

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.



Large accelerated filer ¨		Accelerated filer ¨

Non-accelerated filer x		Smaller reporting company ¨
~~(Do not check if smaller reporting company)~~		Emerging growth company ¨

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). ¨ Yes x No

Indicate the number of shares outstanding of each of the issuer’s classes of common stock, as of the latest practicable date.



Class		April ~~27, 2018~~26, 2019
Common Stock, $0.01 par value		100 shares

Public Service Company of Colorado meets the conditions set forth in General Instruction H (1) (a) and (b) of Form 10-Q and is therefore filing this Form 10-Q with the reduced disclosure format specified in General Instruction H (2) to such Form 10-Q.

TABLE OF CONTENTS



PART I — FINANCIAL INFORMATION

Item l —	Financial Statements (Unaudited)	34
Item 2 —	Management’s Discussion and Analysis of Financial Condition and Results of Operations	2118
Item 4 —	Controls and Procedures	2619

PART II — OTHER INFORMATION

Item 1 —	Legal Proceedings	2620
Item 1A —	Risk Factors	2720
Item 6 —	Exhibits	2720

SIGNATURES		2821

Certifications Pursuant to Section 302		1
Certifications Pursuant to Section 906		1
~~Statement Pursuant to Private Litigation~~		1

This Form 10-Q is filed by Public Service Company of Colorado ~~a Colorado corporation~~ (PSCo). PSCo is a wholly owned subsidiary of Xcel Energy Inc. Xcel Energy Inc. wholly owns the following subsidiaries: Northern States Power Company, a Minnesota corporation (NSP-Minnesota); Northern States Power Company, a Wisconsin corporation (NSP-Wisconsin); PSCo; and Southwestern Public Service Company, a New Mexico corporation (SPS). NSP-Minnesota, NSP-Wisconsin, PSCo and SPS are also referred to collectively as utility subsidiaries. Additional information on Xcel Energy ~~Inc. and its subsidiaries (collectively, Xcel Energy)~~ is available onin various filings with the SEC. This report should be read in its entirety.

ABBREVIATIONS AND INDUSTRY TERMS



Xcel Energy Inc.’s Subsidiaries and Affiliates (current and former)
NSP-Minnesota	Northern States Power Company, a Minnesota corporation
NSP-Wisconsin	Northern States Power Company, a Wisconsin corporation
PSCo	Public Service Company of Colorado
SPS	Southwestern Public Service Company
Utility subsidiaries	NSP-Minnesota, NSP-Wisconsin, PSCo and SPS
WYCO	WYCO Development, LLC
Xcel Energy	Xcel Energy Inc. and subsidiaries

Federal and State Regulatory Agencies
CPUC	Colorado Public Utilities Commission
EPA	United States Environmental Protection Agency
IRS	Internal Revenue Service
SEC	Securities and Exchange Commission

Electric, Purchased Gas and Resource Adjustment Clauses
TCA	Transmission cost adjustment

Other
AFUDC	Allowance for funds used during construction
ARAM	Average rate assumption method
ASC	FASB Accounting Standards Codification
ASU	FASB Accounting Standards Update
C&I	Commercial and Industrial
CCR	Coal combustion residual
CCR Rule	Final rule (40 CFR 257.50 - 257.107) published by the EPA regulating the management, storage and disposal of CCRs as a nonhazardous waste
CIG	Colorado Interstate Gas Company, LLC
CPCN	Certificate of public convenience and necessity
DRC	Development Recovery Company
ETR	Effective tax rate
FASB	Financial Accounting Standards Board
GAAP	Generally accepted accounting principles
IPP	Independent power producing entity
MGP	Manufactured gas plant
NOL	Net operating loss
O&M	Operating and maintenance
PPA	Purchased power agreement
PTC	Production tax credit
ROE	Return on equity
ROU	Right-of-use
TCJA	2017 federal tax reform enacted as Public Law No: 115-97, commonly referred to as the Tax Cuts and Jobs Act

Measurements
MW	Megawatts

Forward-Looking Statements

Except for the historical statements contained in this report, the matters discussed herein are forward-looking statements that are subject to certain risks, uncertainties and ~~Exchange Commission (SEC).~~assumptions. Such forward-looking statements, assumptions and other statements are intended to be identified in this document by the words “anticipate,” “believe,” “could,” “estimate,” “expect,” “intend,” “may,” “objective,” “outlook,” “plan,” “project,” “possible,” “potential,” “should,” “will,” “would” and similar expressions. Actual results may vary materially. Forward-looking statements speak only as of the date they are made, and we expressly disclaim any obligation to update any forward-looking information. The following factors, in addition to those discussed elsewhere in this Quarterly Report on Form 10-Q and in other securities filings (including PSCo’s Annual Report on Form 10-K for the fiscal year ended Dec. 31, 2018 and subsequent securities filings), could cause actual results to differ materially from management expectations as suggested by such forward-looking information: changes in environmental laws and regulations; climate change and other weather natural disaster and resource depletion, including compliance with any accompanying legislative and regulatory changes; ability to recover costs from customers; reductions in our credit ratings and the cost of maintaining certain contractual relationships; general economic conditions, including inflation rates, monetary fluctuations and their impact on capital expenditures and the ability of PSCo and its subsidiaries to obtain financing on favorable terms; availability or cost of capital; our customers’ and counterparties’ ability to pay their debts to us; assumptions and costs relating to funding our employee benefit plans and health care benefits; tax laws; operational safety; successful long-term operational planning; commodity risks associated with energy markets and production; rising energy prices; costs of potential regulatory penalties; effects of geopolitical events, including war and acts of terrorism; cyber security threats and data security breaches; fuel costs; and employee work force and third party contractor factors.

PART I — FINANCIAL INFORMATION

Item 1 — FINANCIAL STATEMENTS

PUBLIC SERVICE CO. OF COLORADO AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED)

(amounts in ~~thousands)~~millions)


	Three Months Ended March 31						Three Months Ended March 31
	2018			2017			2019			2018
Operating revenues
Electric	$	698,274		$	711,388		$	741.5		$	698.3
Natural gas	363,986			356,136			469.1			364.0
Steam and other	11,038			13,010			12.4			11.0
Total operating revenues	1,073,298			1,080,534			1,223.0			1,073.3

Operating expenses
Electric fuel and purchased power	281,170			288,827			304.2			281.2
Cost of natural gas sold and transported	191,265			196,402			272.5			191.3
Cost of sales — steam and other	3,876			4,386			4.4			3.9
Operating and maintenance expenses	183,075			185,088			199.3			183.1
Demand side management expenses	32,752			28,104			32.1			32.7
Depreciation and amortization	121,607			114,994			146.9			121.6
Taxes (other than income taxes)	52,657			49,798			53.7			52.6
Total operating expenses	866,402			867,599			1,013.1			866.4

Operating income	206,896			212,935			209.9			206.9

Other income, net	231			3,204			1.0			0.2
Allowance for funds used during construction — equity	10,944			4,608			4.1			10.9

Interest charges and financing costs
Interest charges — includes other financing costs of $1,572 and $1,521, respectively	49,921			45,882
Interest charges — includes other financing costs of $1.6 and $1.6, respectively							59.5			49.9
Allowance for funds used during construction — debt	(4,581		)	(1,906		)	(2.4		)	(4.6		)
Total interest charges and financing costs	45,340			43,976			57.1			45.3

Income before income taxes	172,731			176,771			157.9			172.7
Income taxes	39,009			65,225			19.1			39.0
Net income	$	133,722		$	111,546		$	138.8		$	133.7

See Notes to Consolidated Financial Statements

PUBLIC SERVICE CO. OF COLORADO AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED)

(amounts in ~~thousands)~~millions)


	Three Months Ended March 31				Three Months Ended March 31
	2018		2017		2019		2018
Net income	$	133,722	$	111,546	$	138.8	$	133.7

Other comprehensive income (loss)

Pension and retiree medical benefits:
Amortization of losses included in net periodic benefit cost, net of tax of $1, and $1, respectively	2		1
Other comprehensive income

Derivative instruments:
Reclassification of losses to net income, net of tax of $98 and $152, respectively	300		246
Reclassification of losses to net income, net of tax of $0.1, and $0.1, respectively					0.3		0.3

Other comprehensive income	302		247		0.3		0.3
Comprehensive income	$	134,024	$	111,793	$	139.1	$	134.0

See Notes to Consolidated Financial Statements

PUBLIC SERVICE CO. OF COLORADO AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED)

(amounts in ~~thousands)~~millions)


	Three Months Ended March 31						Three Months Ended March 31
	2018			2017			2019			2018
Operating activities
Net income	$	133,722		$	111,546		$	138.8		$	133.7
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	122,802			115,803			148.2			122.8
Demand side management program amortization	—			336
Deferred income taxes	13,168			61,726			(1.2		)	13.2
Amortization of investment tax credits	(700		)	(701		)	(0.6		)	(0.7		)
Allowance for equity funds used during construction	(10,944		)	(4,608		)	(4.1		)	(10.9		)
Net realized and unrealized hedging and derivative transactions	1,807			1,679			(2.6		)	1.8
Changes in operating assets and liabilities:
Accounts receivable	(19,358		)	1,086			(54.7		)	(19.4		)
Accrued unbilled revenues	58,369			91,100			32.2			58.4
Inventories	60,563			43,667			33.5			60.6
Prepayments and other	1,330			659			(9.3		)	1.3
Accounts payable	(25,773		)	(65,886		)	(45.7		)	(25.8		)
Net regulatory assets and liabilities	31,072			14,345			93.2			31.1
Other current liabilities	465			17,860			42.6			0.5
Pension and other employee benefit obligations	(22,803		)	(16,506		)	(43.7		)	(22.8		)
Change in other noncurrent assets	2,465			936
Change in other noncurrent liabilities	(7,435		)	479
Other, net							1.9			(5.0		)
Net cash provided by operating activities	338,750			373,521			328.5			338.8

Investing activities
Utility capital/construction expenditures	(426,730		)	(272,927		)	(282.9		)	(415.8		)
Allowance for equity funds used during construction	10,944			4,608
Investments in utility money pool arrangement	(36,000		)	(38,000		)	(131.0		)	(36.0		)
Repayments from utility money pool arrangement	56,000			38,000			131.0			56.0
Net cash used in investing activities	(395,786		)	(268,319		)	(282.9		)	(395.8		)

Financing activities
Repayments of short-term borrowings, net	95,000			(98,000		)	(68.0		)	95.0
Borrowings under utility money pool arrangement	158,000			40,000			—			158.0
Repayments under utility money pool arrangement	(110,000		)	(40,000		)	—			(110.0		)
Proceeds from issuance of long-term debt							392.6			—
Repayments of long-term debt							(400.0		)	—
Capital contributions from parent	6,508			67,475			112.2			6.5
Dividends paid to parent	(76,195		)	(74,208		)	(91.6		)	(76.2		)
Other	(117		)	(110		)
Net cash provided by (used in) financing activities	73,196			(104,843		)
Other, net							—			(0.1		)
Net cash (used in) provided by financing activities							(54.8		)	73.2

Net change in cash and cash equivalents	16,160			359			(9.2		)	16.2
Cash and cash equivalents at beginning of period	7,513			5,926			33.4			7.5
Cash and cash equivalents at end of period	$	23,673		$	6,285		$	24.2		$	23.7

Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	$	(60,064	)	$	(61,252	)	$	(65.3	)	$	(60.1	)
Cash paid for income taxes, net	(46,482		)	(4,804		)	(10.7		)	(46.5		)
Supplemental disclosure of non-cash investing transactions:
Property, plant and equipment additions in accounts payable	$	128,493		$	69,885
Supplemental disclosure of non-cash investing and financing transactions:
Accrued property, plant and equipment additions							$	85.1		$	128.5
Inventory transfers to property, plant and equipment							6.9			4.1
Operating lease right-of-use assets							652.8			—
Allowance for equity funds used during construction							4.1			10.9

See Notes to Consolidated Financial Statements

PUBLIC SERVICE CO. OF COLORADO AND SUBSIDIARIES

CONSOLIDATED BALANCE SHEETS (UNAUDITED)

(amounts in ~~thousands,~~millions, except share and per share data)


	March 31, 2018			Dec. 31, 2017			March 31, 2019			Dec. 31, 2018
Assets
Current assets
Cash and cash equivalents	$	23,673		$	7,513		$	24.2		$	33.4
Accounts receivable, net	312,526			294,403			373.1			310.3
Accounts receivable from affiliates	9,446			14,719			10.5			80.8
Investments in utility money pool arrangement	—			20,000
Accrued unbilled revenues	237,432			295,801			281.3			313.5
Inventories	153,926			214,489			156.9			197.4
Regulatory assets	68,164			77,337			67.7			120.6
Derivative instruments	4,897			3,197			30.1			42.6
Prepayments and other	34,390			35,720			32.9			23.8
Total current assets	844,454			963,179			976.7			1,122.4

Property, plant and equipment, net	14,291,475			14,025,751			15,090.1			15,120.0

Other assets
Regulatory assets	945,739			950,258			1,029.6			1,010.7
Derivative instruments	1,093			1,009			2.6			1.2
Operating lease right-of-use assets							633.0			—
Other	24,494			27,429			177.0			37.2
Total other assets	971,326			978,696			1,842.2			1,049.1
Total assets	$	16,107,255		$	15,967,626		$	17,909.0		$	17,291.5

Liabilities and Equity
Current liabilities
Current portion of long-term debt	$	305,721		$	305,577		$	—		$	406.2
Short-term debt	95,000			—			239.0			307.0
Borrowings under utility money pool arrangement	48,000			—
Accounts payable	430,515			492,829			428.5			503.4
Accounts payable to affiliates	38,830			58,749			35.0			46.0
Regulatory liabilities	79,080			66,126			104.5			67.3
Taxes accrued	249,359			222,517			271.9			202.0
Accrued interest	33,640			48,552			33.5			43.2
Dividends payable to parent	95,351			76,195			98.8			91.5
Derivative instruments	7,344			7,348			20.2			34.6
Other	82,041			92,333			170.3			101.5
Total current liabilities	1,464,881			1,370,226			1,401.7			1,802.7

Deferred credits and other liabilities
Deferred income taxes	1,661,220			1,644,476			1,726.2			1,719.3
Deferred investment tax credits	27,158			27,858			24.7			25.3
Regulatory liabilities	1,943,401			1,933,488			2,041.2			2,021.5
Asset retirement obligations	351,379			347,769			342.5			338.7
Derivative instruments	2,367			3,468			1.1			0.6
Customer advances	170,262			162,614			170.0			168.1
Pension and employee benefit obligations	264,668			287,783			231.2			275.3
Operating lease liabilities							581.1			—
Other	52,819			58,923			154.7			50.4
Total deferred credits and other liabilities	4,473,274			4,466,379			5,272.7			4,599.2

Commitments and contingencies
Capitalization
Long-term debt	4,302,104			4,302,698			4,846.1			4,591.4
Common stock — 100 shares authorized at $0.01 par value; 100 shares outstanding at March 31, 2018 and Dec. 31, 2017, respectively	—			—
Common stock — 100 shares authorized at $0.01 par value; 100 shares outstanding at March 31, 2019 and Dec. 31, 2018, respectively							—			—
Additional paid in capital	4,032,826			4,032,826			4,390.5			4,340.5
Retained earnings	1,860,600			1,822,229			2,023.2			1,983.2
Accumulated other comprehensive loss	(26,430		)	(26,732		)	(25.2		)	(25.5		)
Total common stockholder’s equity	5,866,996			5,828,323			6,388.5			6,298.2
Total liabilities and equity	$	16,107,255		$	15,967,626		$	17,909.0		$	17,291.5

See Notes to Consolidated Financial Statements

PUBLIC SERVICE CO. OF COLORADO AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF COMMON STOCKHOLDER’S EQUITY (UNAUDITED)

(amounts in millions, except share data)



	Common Stock Issued					Retained Earnings			Accumulated Other Comprehensive Loss			Total Common Stockholder’s Equity
	Shares	Par Value		Additional Paid In Capital		Retained Earnings			Accumulated Other Comprehensive Loss			Total Common Stockholder’s Equity
Three Months Ended March 31, 2019 and 2018
Balance at Dec. 31, 2017	100	$	—	$	4,032.8	$	1,822.2		$	(26.7	)	$	5,828.3
Net income						133.7						133.7
Other comprehensive income									0.3			0.3
Dividends declared to parent						(95.3		)				(95.3		)
Contribution of capital by parent				—								—
Balance at March 31, 2018	100	$	—	$	4,032.8	$	1,860.6		$	(26.4	)	$	5,867.0

Balance at Dec. 31, 2018	100	$	—	$	4,340.5	$	1,983.2		$	(25.5	)	$	6,298.2
Net income						138.8						138.8
Other comprehensive income									0.3			0.3
Dividends declared to parent						(98.8		)				(98.8		)
Contribution of capital by parent				50.0								50.0
Balance at March 31, 2019	100	$	—	$	4,390.5	$	2,023.2		$	(25.2	)	$	6,388.5

See Notes to Consolidated Financial Statements

PUBLIC SERVICE CO. OF COLORADO AND SUBSIDIARIES

Notes to Consolidated Financial Statements (UNAUDITED)

In the opinion of management, the accompanying unaudited consolidated financial statements contain all adjustments necessary to present fairly, in accordance with ~~accounting principles generally accepted in the United States of America (GAAP),~~GAAP, the financial position of PSCo and its subsidiaries as of March 31, ~~2018~~2019 and Dec. 31, ~~2017;~~2018; the results of its operations, including the components of net income and comprehensive income, and changes in stockholders’ equity for the three months ended March 31, ~~2018~~2019 and ~~2017;~~2018; and its cash flows for the three months ended March 31, ~~2018~~2019 and ~~2017.~~2018. All adjustments are of a normal, recurring nature, except as otherwise disclosed. Management has also evaluated the impact of events occurring after March 31, ~~2018~~2019 up to the date of issuance of these consolidated financial statements. These statements contain all necessary adjustments and disclosures resulting from that evaluation. The Dec. 31, ~~2017~~2018 balance sheet information has been derived from the audited ~~2017~~2018 consolidated financial statements included in the PSCo Annual Report on Form 10-K for the year ended Dec. 31, ~~2017.~~2018. These notes to the consolidated financial statements have been prepared pursuant to the rules and regulations of the SEC for Quarterly Reports on Form 10-Q. Certain information and note disclosures normally included in financial statements prepared in accordance with GAAP on an annual basis have been condensed or omitted pursuant to such rules and regulations. For further information, refer to the consolidated financial statements and notes thereto, included in the PSCo Annual Report on Form 10-K for the year ended Dec. 31, ~~2017,~~2018, filed with the SEC on Feb. ~~23, 2018.~~22, 2019. Due to the seasonality of PSCo’s electric and natural gas sales, interim results are not necessarily an appropriate base from which to project annual results.


1.	Summary of Significant Accounting Policies

The significant accounting policies set forth in Note 1 to the consolidated financial statements in the PSCo Annual Report on Form 10-K for the year ended Dec. 31, ~~2017,~~2018, appropriately represent, in all material respects, the current status of accounting policies and are incorporated herein by reference.


2.	Accounting Pronouncements

Recently Issued

~~Leases —~~Credit Losses I—~~n February~~ In 2016, the ~~Financial Accounting Standards Board (FASB)~~FASB issued ~~Leases,~~Financial Instruments - Credit Losses, Topic ~~842 (Accounting Standards Update (ASU) No. 2016-02)~~326 (ASC Topic 326), , which changes how entities account for ~~lessees~~credit losses on receivables and certain other assets. The guidance requires ~~balance sheet~~use of a current expected loss model, which may result in earlier recognition of ~~right-of-use assets and lease liabilities for most leases. This guidance will be~~credit losses than under previous accounting standards. ASC Topic 326 is effective for interim and annual ~~reporting~~ periods beginning on or after Dec. 15, ~~2018.~~2019. PSCo ~~has not yet fully determined~~is currently evaluating the ~~impacts~~impact of ~~implementation. However,~~ adoption ~~is expected to occur on Jan. 1, 2019 utilizing the practical expedients provided by the standard and proposed in~~ ~~Targeted Improvements, Topic 842 (Proposed ASU 2018-200). As such, agreements entered into prior to Jan. 1, 2019 that are currently considered leases are expected to be recognized on the consolidated balance sheet, including contracts for use~~ of office space, equipment and natural gas storage assets, as well as certain purchased power agreements (PPAs) for natural gas-fueled generating facilities. PSCo expects that similar agreements entered into after Dec. 31, 2018 will generally qualify as leases under the new ~~standard.~~standard on its consolidated financial statements.

Recently Adopted

~~Revenue Recognition~~Leases —In ~~May 2014,~~2016, the FASB issued ~~Revenue from Contracts with Customers,~~ Leases, Topic ~~606 (ASU No. 2014-09)~~842(ASC Topic 842), which provides a new ~~framework~~accounting and disclosure guidance for leasing activities, most significantly requiring that operating leases be recognized on the ~~recognition of revenue.~~balance sheet. PSCo ~~implemented~~adopted the guidance on ~~a modified retrospective basis on~~ Jan. 1, ~~2018. Results~~2019 utilizing the package of transition practical expedients provided by the new standard, including carrying forward prior conclusions on whether agreements existing before the adoption date contain leases and whether existing leases are operating or finance leases; ASC Topic 842 refers to capital leases as finance leases.

Specifically for land easement contracts, PSCo has elected the practical expedient provided by ASU No. 2018-01 Leases: Land Easement Practical Expedient for Transition to Topic 842, and as a result, only those easement contracts entered on or after Jan. 1, 2019 will be evaluated to determine if lease treatment is appropriate.

PSCo also utilized the transition practical expedient offered by ASU No. 2018-11 Leases: Targeted Improvements to implement the standard on a prospective basis. As a result, reporting periods in the consolidated financial statements beginning ~~after Dec. 31, 2017 are presented in accordance with~~Jan. 1, 2019 reflect the implementation of ASC Topic ~~606,~~842, while prior ~~period results have not been adjusted and~~periods continue to be reported in accordance with ~~prior accounting guidance.~~Leases, Topic 840 (ASC Topic 840). Other than ~~increased disclosures regarding revenues related to contracts with customers,~~first-time recognition of operating leases on its consolidated balance sheet, the implementation of ASC Topic 842 did not have a significant impact on PSCo’s consolidated financial statements. ~~For related disclosures, see Note 13.~~

~~Classification and Measurement~~Adoption resulted in recognition of ~~Financial Instruments —~~ ~~In January 2016, the FASB issued~~ ~~Recognition and Measurement of Financial Assets and Financial Liabilities, Subtopic 825-10 (ASU No. 2016-01)~~, which eliminated the available-for-sale classification for marketable equity securities and also replaced the cost method of accounting for non-marketable equity securities with a model for recognizing impairments and observable price changes. Under the new standard, other than when the consolidation or equity method of accounting is utilized, changes in the fair value of equity securities are recognized in earnings. PSCo implemented the guidance on Jan. 1, 2018 and the implementation did not have a material impact on its consolidated financial statements.

~~Presentation of Net Periodic Benefit Cost —~~I~~n March 2017, the FASB issued~~ ~~Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost, Topic 715 (ASU No. 2017-07), which establishes that only the service cost element of pension cost may be presented as a component~~approximately $0.7 billion of operating ~~income in the income statement. Also under the guidance, only the service cost component of pension cost is eligible~~lease ROU assets and current/noncurrent operating lease liabilities. See Note 9 for capitalization. As a result of application of accounting principles for rate regulated entities, a similar amount of pension cost, including non-service components, will be recognized consistent with the historical ratemaking treatment, and the impacts of adoption will be limited to changes in classification of non-service costs in the consolidated statement of income. PSCo implemented the new guidance on Jan. 1, 2018, and as a result, $0.5 million of pension costs were retrospectively reclassified from operating and maintenance expenses to other income, net on the consolidated income statement for the three months ended March 31, 2017. Under a practical expedient permitted by the standard, PSCo used benefit cost amounts disclosed for prior periods as the basis for retrospective application.leasing disclosures.


3.	Selected Balance Sheet Data


(Thousands of Dollars)	March 31, 2018			Dec. 31, 2017
(Millions of Dollars)							March 31, 2019			Dec. 31, 2018
Accounts receivable, net
Accounts receivable	$	332,506		$	314,009		$	394.2		$	330.8
Less allowance for bad debts	(19,980		)	(19,606		)	(21.1		)	(20.5		)
	$	312,526		$	294,403		$	373.1		$	310.3


(Thousands of Dollars)	March 31, 2018		Dec. 31, 2017
(Millions of Dollars)					March 31, 2019		Dec. 31, 2018
Inventories
Materials and supplies	$	69,378	$	68,940	$	62.4	$	61.9
Fuel	53,282		73,893		64.5		69.5
Natural gas	31,266		71,656		30.0		66.0
	$	153,926	$	214,489	$	156.9	$	197.4


(Thousands of Dollars)	March 31, 2018			Dec. 31, 2017
(Millions of Dollars)							March 31, 2019			Dec. 31, 2018
Property, plant and equipment, net
Electric plant	$	12,692,880		$	12,627,592		$	13,733.3		$	13,604.5
Natural gas plant	4,140,582			4,102,075			4,321.5			4,387.6
Common and other property	1,031,570			1,022,333			1,040.4			1,023.7
Plant to be retired ^(a)	10,627			10,949			305.7			321.9
Construction work in progress	1,264,835			1,014,338			581.7			573.3
Total property, plant and equipment	19,140,494			18,777,287			19,982.6			19,911.0
Less accumulated depreciation	(4,849,019		)	(4,751,536		)	(4,892.5		)	(4,791.0		)
	$	14,291,475		$	14,025,751		$	15,090.1		$	15,120.0

^(a)

In 2018, the ~~third quarter~~CPUC approved early retirement of ~~2017, PSCo early retired Valmont Unit 5~~PSCo’s Comanche Units 1 and ~~converted Cherokee Unit 4 from a coal-fueled generating facility to natural gas.~~2 in approximately 2022 and 2025, respectively. PSCo also expects Craig Unit 1 to be retired early ~~retired~~ in ~~approximately~~ 2025. Amounts are presented net of accumulated depreciation.


4.	~~Income Taxes~~

Except to the extent noted below, Note 7 to the consolidated financial statements included in PSCo’s Annual Report on Form 10-K for the year ended Dec. 31, 2017 appropriately represents, in all material respects, the current status of other income tax matters, and are incorporated herein by reference.

Total income tax expense from operations differs from the amount computed by applying the statutory federal income tax rate to income before income tax expense. The following reconciles such differences:

Three Months ended March 31
2018 2017
Federal statutory rate 21.0 % 35.0 %
State tax, net of federal tax effect 3.7
3.0
Increases (decreases) in tax from:
Regulatory differences - ARAM^(a)
(3.3 ) (0.1 )
Regulatory differences - ARAM deferral ^(b)
3.1
—
Regulatory differences - other utility plant items (1.3 ) (0.4 )
Other tax credits, net of federal income tax expense (1.0 ) (0.7 )
Other, net 0.4
0.1
Effective income tax rate 22.6 % 36.9 %


^(a)	~~The average rate assumption method (ARAM); a method to flow back excess deferred taxes to customers.~~


^(b)	As we receive further clarity or direction from our commissions regarding the flow back to customers of excess deferred taxes resulting from the TCJA, the ARAM deferral may decrease during the year, which would result in a reduction to tax expense with a correlating reduction to revenue.

~~Federal Audits~~— PSCO is a member of the Xcel Energy affiliated group that files a consolidated federal income tax return. The statute of limitations applicable to Xcel Energy’s federal income tax returns expire as follows:



~~Tax Year(s)~~		~~Expiration~~
~~2009 - 2011~~		~~December 2018~~
~~2012 - 2013~~		~~October 2018~~
~~2014~~		~~September 2018~~
~~2015~~		~~September 2019~~
~~2016~~		~~September 2020~~

In 2012, the Internal Revenue Service (IRS) commenced an examination of tax years 2010 and 2011, including the 2009 carryback claim. The IRS proposed an adjustment to the federal tax loss carryback claims and in 2015, the IRS forwarded the issue to the Office of Appeals (“Appeals”). In 2017 Xcel Energy and Appeals reached an agreement and the benefit related to the agreed upon portions was recognized. PSCo did not accrue any income tax benefit related to this adjustment. As of March 31, 2018, the case has been forwarded to the Joint Committee on Taxation.

In the third quarter of 2015, the IRS commenced an examination of tax years 2012 and 2013. In the third quarter of 2017, the IRS concluded the audit of tax years 2012 and 2013 and proposed an adjustment that would impact Xcel Energy’s net operating loss (NOL) and effective tax rate (ETR). After evaluating the proposed adjustment Xcel Energy filed a protest with the IRS. Xcel Energy anticipates the issue will be forwarded to Appeals. As of March 31, 2018, Xcel Energy has recognized its best estimate of income tax expense that will result from a final resolution of this issue; however, the outcome and timing of a resolution is uncertain.

~~State Audits~~ — PSCo is a member of the Xcel Energy affiliated group that files consolidated state income tax returns. As of March 31, 2018, PSCo’s earliest open tax year that is subject to examination by state taxing authorities under applicable statutes of limitations is 2009. There are currently no state income tax audits in progress.

~~Unrecognized Benefits~~— The unrecognized tax benefit balance includes permanent tax positions, which if recognized would affect the annual ETR. In addition, the unrecognized tax benefit balance includes temporary tax positions for which the ultimate deductibility is highly certain but for which there is uncertainty about the timing of such deductibility. A change in the period of deductibility would not affect the ETR but would accelerate the payment of cash to the taxing authority to an earlier period.

~~A reconciliation of the amount of unrecognized tax benefit is as follows:~~

(Millions of Dollars) March 31, 2018 Dec. 31, 2017
Unrecognized tax benefit — Permanent tax positions $ 4.1
$ 4.0
Unrecognized tax benefit — Temporary tax positions 6.0
6.1
Total unrecognized tax benefit $ 10.1
$ 10.1

The unrecognized tax benefit amounts were reduced by the tax benefits associated with NOL and tax credit carryforwards. The amounts of tax benefits associated with NOL and tax credit carryforwards are as follows:

(Millions of Dollars) March 31, 2018 Dec. 31, 2017
NOL and tax credit carryforwards $ (4.2 ) $ (4.0 )

It is reasonably possible that PSCo’s amount of unrecognized tax benefits could significantly change in the next 12 months as the IRS Appeals progresses and the IRS and state audits resume. As the IRS Appeals progresses, it is reasonably possible that the amount of unrecognized tax benefit could decrease up to approximately~~$6 million.~~

The payable for interest related to unrecognized tax benefits is partially offset by the interest benefit associated with NOL and tax credit carryforwards. The payables for interest related to unrecognized tax benefits at March 31, 2018, and Dec. 31, 2017 were not material. No amounts were accrued for penalties related to unrecognized tax benefits as of March 31, 2018 or Dec. 31, 2017.


5.	~~Rate Matters~~

Except to the extent noted below, the circumstances set forth in Note 11 to the consolidated financial statements included in PSCo’s Annual Report on Form 10-K for the year ended Dec. 31, 2017, appropriately represent, in all material respects, the current status of other rate matters, and are incorporated herein by reference.

~~Tax Reform~~ — ~~Regulatory Proceedings~~

The specific impacts of the Tax Cuts and Jobs Act (TCJA) on customer rates are subject to regulatory approval. Each of the states in Xcel Energy’s service areas, including Colorado, have opened dockets to address the impacts of the TCJA. PSCo has made filings and is working with various stakeholders to determine the appropriate treatment for the TCJA.

~~In January 2018, the Colorado Public Utilities Commission (CPUC) opened a statewide TCJA proceeding and ordered deferred accounting for all investor-owned utilities.~~

~~Colorado 2017 Multi-Year Natural Gas Rate Case~~- In February 2018, the administrative law judge (ALJ) approved PSCo and the CPUC Staff’s settlement agreement addressing the TCJA, which includes a $20 million reduction to provisional rates effective March 1, 2018. A final true-up, including any outcomes associated with the statewide proceeding, would provide customers the full net benefit of the TCJA effective January 2018. A CPUC decision is pending.

~~Colorado Electric~~- In April 2018, PSCo, the CPUC Staff and the OCC filed a TCJA settlement agreement with the CPUC that identified a reduction in electric revenue requirements of approximately $101 million for the TCJA in 2018. The settlement recommended a customer refund of $42 million in 2018, with the remainder of $59 million be used to accelerate the amortization of an existing prepaid pension asset. With the dismissal of the 2017 rate case, revisions to the TCJA settlement are required to address the impacts of the TCJA for 2019 until new base rates go into effect in connection with a future electric rate case that PSCo anticipates filing later this summer. A CPUC decision is pending.

~~Federal Energy Regulatory Commission (FERC) Formula Rates~~ — The FERC has not yet issued guidance on how or when electric utilities should reflect the impacts of the TCJA in FERC jurisdictional wholesale rates. The FERC issued a Notice of Inquiry (NOI) in March 2018 seeking comments on how to reflect the TCJA impacts in wholesale rates, in particular changes to accumulated deferred income taxes and bonus depreciation. Comments for the NOI are due in May 2018. However, FERC-approved formula rates for wholesale customers are generally adjusted on an annual basis for certain changes in rate base and actual operating expenses, including income taxes. As a result, these revenues would be subject to an automatic reduction for the effect of the TCJA corporate tax rate change through the annual true-up process, absent specific FERC action.

In February 2018, PSCo made a filing with FERC requesting early reductions in its transmission and production formula rates in 2018 for corporate tax rate impacts of the TCJA. In March 2018, the FERC issued an order granting PSCo’s waiver request so that 2018 rates will reflect the lower federal corporate tax rate.

~~Pending Regulatory Proceedings — CPUC~~

~~Colorado 2017 Multi-Year Electric Rate Case~~ — In October 2017, PSCo filed a multi-year request with the CPUC seeking to increase electric rates approximately $245 million over four years. The request was based on forecast test years (FTY), a 10.0 percent return on equity (ROE) and an equity ratio of 55.25 percent. Interim rates, subject to refund and interest, were to be effective on June 1, 2018.

Revenue Request (Millions of Dollars) 2018 2019 2020 2021 Total
Revenue request $ 74
$ 75
$ 60
$ 36
$ 245
Clean Air Clean Jobs Act (CACJA) rider conversion to base rates 90
—
—
—
90
Transmission Cost Adjustment (TCA) rider conversion to base rates 43
—
—
—
43
Total $ 207
$ 75
$ 60
$ 36
$ 378

Expected year-end rate base (billions of dollars) $ 6.8
$ 7.1
$ 7.3
$ 7.4

In March 2018, PSCo, CPUC Staff and OCC reached a settlement and filed a motion with the CPUC requesting changes to the procedural schedule and scope of the electric case, which included delaying the implementation of provisional rates from June 2018 to January 2019 and requiring PSCo to file updated test year information for 2019-2021 which included the impacts of TCJA. In April 2018, the CPUC denied the motion on procedural grounds and dismissed the electric rate case. PSCo anticipates filing a new electric rate case in the summer of 2018 with new rates expected to be effective in the first quarter of 2019.

~~Colorado 2017 Multi-Year Natural Gas Rate Case~~ — In June 2017, PSCo filed a multi-year request with the CPUC seeking to increase retail natural gas rates approximately $139 million over three years. The request, detailed below, is based on FTYs, a 10.0 percent ROE and an equity ratio of 55.25 percent.

Revenue Request (Millions of Dollars) 2018 2019 2020 Total
Revenue request $ 63
$ 33
$ 43
$ 139
Pipeline System Integrity Adjustment (PSIA) rider conversion to base rates ^(a)
—
94
—
94
Total $ 63
$ 127
$ 43
$ 233

Expected year-end rate base (billions of dollars) ^(b)
$ 1.5
$ 2.3
$ 2.4


^(a)	The roll-in of PSIA rider revenue into base rates will not have an impact on customer bills or revenue as these costs are already being recovered through the rider. The recovery of incremental PSIA related investments in 2019 and 2020 are included in the base rate request.


^(b)	~~The additional rate base in 2019 predominantly reflects the roll-in of capital associated with the PSIA rider.~~

In October 2017, the CPUC Staff and the OCC recommended a single 2016 historic test year (HTY) based on an average 13-month rate base, and opposed a multi-year request. In addition, they recommended an equity ratio of 48.73 percent and 51.2 percent, respectively, and the existing PSIA rider expire with the 2018 rates rolled into base rates beginning Jan. 1, 2019. Planned investments in 2019 and 2020 would be recoverable through a future rate case. The Staff and OCC provide for a recommended 2018 rate increase of approximately $30 million and $39 million, respectively.

~~Provisional rates, subject to refund, of $63 million were implemented on Jan. 1, 2018.~~

On Jan. 31, 2018, the CPUC ordered deferred accounting for the impacts of TCJA and opened a statewide TCJA proceeding, as discussed below. In February 2018, the ALJ approved a settlement agreement between PSCo and the CPUC, which reduced provisional rates by $20 million to address the impacts of the TCJA. The CPUC is expected to rule on the regulatory treatment of the TCJA and the natural gas rate case later in 2018.

~~On April 20, 2018, PSCo filed for a PSIA extension through 2020 in the event that the CPUC does not adopt its multi-year plan proposal.~~


6.	~~Commitments and Contingencies~~

Except to the extent noted below and in Note 5 above, the circumstances set forth in Notes 11 and 12 to the consolidated financial statements included in PSCo’s Annual Report on Form 10-K for the year ended Dec. 31, 2017, appropriately represent, in all material respects, the current status of commitments and contingent liabilities and are incorporated herein by reference. The following include commitments, contingencies and unresolved contingencies that are material to PSCo’s financial position.

~~PPAs~~

Under certain PPAs, PSCo purchases power from independent power producing entities that own natural gas fueled power plants for which PSCo is required to reimburse natural gas fuel costs, or to participate in tolling arrangements under which PSCo procures the natural gas required to produce the energy that it purchases. These specific PPAs create a variable interest in the associated independent power producing entity.

PSCo had approximately 1,571 megawatts (MW) of capacity under long-term PPAs as of March 31, 2018 and Dec. 31, 2017, with entities that have been determined to be variable interest entities. PSCo has concluded that these entities are not required to be consolidated in its consolidated financial statements because it does not have the power to direct the activities that most significantly impact the entities’ economic performance. These agreements have expiration dates through 2032.

~~Environmental Contingencies~~

~~Manufactured Gas Plant (MGP), Landfill or Disposal Sites~~ — PSCo is currently involved in investigating and/or remediating several MGP, landfill or other disposal sites. PSCo has identified two sites where contamination is present and where investigation and/or remediation activities are currently underway. Other parties may have responsibility for some portion of the investigation and/or remediation activities that are underway. PSCo anticipates that these investigation or remediation activities will continue through at least 2018. PSCo had accrued $1 million as of March 31, 2018 and an immaterial amount as of Dec. 31, 2017, for these sites. There may be insurance recovery and/or recovery from other potentially responsible parties that will offset any costs incurred. PSCo anticipates that any amounts spent will be fully recovered from customers.

~~Legal Contingencies~~

PSCo is involved in various litigation matters that are being defended and handled in the ordinary course of business. The assessment of whether a loss is probable or is a reasonable possibility, and whether the loss or a range of loss is estimable, often involves a series of complex judgments about future events. Management maintains accruals for such losses that are probable of being incurred and subject to reasonable estimation. Management is sometimes unable to estimate an amount or range of a reasonably possible loss in certain situations, including but not limited to when (1) the damages sought are indeterminate, (2) the proceedings are in the early stages, or (3) the matters involve novel or unsettled legal theories. In such cases, there is considerable uncertainty regarding the timing or ultimate resolution of such matters, including a possible eventual loss. For current proceedings not specifically reported herein, management does not anticipate that the ultimate liabilities, if any, arising from such current proceedings would have a material effect on PSCo’s financial statements. Unless otherwise required by GAAP, legal fees are expensed as incurred.

~~Employment, Tort and Commercial Litigation~~

~~Line Extension Disputes~~ — In December 2015, Development Recovery Company (DRC) filed a lawsuit in the Denver District Court, stating PSCo failed to award proper allowances and refunds for line extensions to new developments pursuant to the terms of electric and gas service agreements entered into by PSCo and various developers. The dispute involved claims by over fifty developers. In February 2018, the Colorado Supreme Court denied DRC’s petition to appeal the Denver District Court’s dismissal of the lawsuit, effectively terminating this litigation. However, in January 2018, DRC filed a new lawsuit in Boulder County District Court, asserting a single claim that PSCo was required to file its line extension agreements with the CPUC but failed to do so. This claim is substantially similar to the arguments previously raised by DRC. In February 2018, PSCo filed a motion to dismiss. Dates for this proceeding have not been scheduled.

PSCo has concluded that a loss is remote with respect to this matter as the service agreements were developed to implement CPUC approved tariffs and PSCo has complied with the tariff provisions. Also, if a loss were sustained, PSCo believes it would be allowed to recover these costs through traditional regulatory mechanisms. The amount or range in dispute is presently unknown and no accrual has been recorded for this matter.


7.	Borrowings and Other Financing Instruments

Short-Term Borrowings

PSCo meets its short-term liquidity requirements primarily through the issuance of commercial paper and borrowings under its credit facility and the money pool.

Money Pool — Xcel Energy Inc. and its utility subsidiaries have established a money pool arrangement that allows for short-term investments in and borrowings between the utility subsidiaries. Xcel Energy Inc. may make investments in the utility subsidiaries at market-based interest rates; however, the money pool arrangement does not allow the utility subsidiaries to make investments in Xcel Energy Inc. Money pool borrowings for PSCo were as follows:


(Amounts in Millions, Except Interest Rates)	Three Months Ended March 31, 2018			Year Ended Dec. 31, 2017			Three Months Ended March 31, 2019		Year Ended Dec. 31, 2018
Borrowing limit	$	250		$	250		$	250	$	250
Amount outstanding at period end	48			—			—		—
Average amount outstanding	12			—			—		25
Maximum amount outstanding	97			20			—		156
Weighted average interest rate, computed on a daily basis	1.64		%	0.92		%	N/A		1.93		%
Weighted average interest rate at period end	1.64			N/A			N/A		N/A

Commercial Paper — ~~PSCo meets its short-term liquidity requirements primarily through the issuance of commercial paper and borrowings under its credit facility and the money pool.~~ Commercial paper outstanding for PSCo was as follows:


(Amounts in Millions, Except Interest Rates)	Three Months Ended March 31, 2018			Year Ended Dec. 31, 2017			Three Months Ended March 31, 2019			Year Ended Dec. 31, 2018
Borrowing limit	$	700		$	700		$	700		$	700
Amount outstanding at period end	95			—			239			307
Average amount outstanding	50			54			245			55
Maximum amount outstanding	151			268			414			309
Weighted average interest rate, computed on a daily basis	1.82		%	1.08		%	2.78		%	2.28		%
Weighted average interest rate at period end	2.28			N/A			2.68			2.95

Letters of Credit — PSCo uses letters of credit, generally with terms of one year, to provide financial guarantees for certain operating obligations. At both March 31, ~~2018~~2019 and Dec. 31, ~~2017,~~2018, there were $4$10 million ~~and $3 million, respectively~~ of letters of credit outstanding under the credit facility. The contract amounts of these letters of credit approximate their fair value and are subject to fees.

Credit Facility — In order to use its commercial paper program to fulfill short-term funding needs, PSCo must have a revolving credit facility in place at least equal to the amount of its commercial paper borrowing limit and cannot issue commercial paper in an aggregate amount exceeding available capacity under this credit facility. The credit facility provides short-term financing in the form of notes payable to banks, letters of credit and back-up support for commercial paper borrowings.

At March 31, ~~2018,~~2019, PSCo had the following committed credit facility available (in millions of dollars):


Credit Facility ^(a)	Credit Facility ^(a)	Drawn ^(b)		Available		Credit Facility ^(a)	Outstanding ^(b)		Available
$	700	$	99	$	601	700	$	249	$	451

^(a) This credit facility expires in June 2021.

^(b) Includes outstanding commercial paper and letters of credit.

All credit facility bank borrowings, outstanding letters of credit and outstanding commercial paper reduce the available capacity under the credit facility. PSCo had no direct advances on the credit facility outstanding at March 31, ~~2018~~2019 and Dec. 31, ~~2017.~~2018.

Long-Term Borrowings

During the three months ended March 31, 2019, PSCo issued $400 million of 4.05% first mortgage bonds due Sep 15, 2049.


8.5.	Revenues

Revenue is classified by the type of goods/services rendered and market/customer type. PSCo’s operating revenues consists of the following:



	Three Months Ended March 31, 2019
(Millions of Dollars)	Electric		Natural Gas		All Other		Total
Major revenue types
Revenue from contracts with customers:
Residential	$	245.1	$	311.4	$	2.5	$	559.0
C&I	367.9		120.3		8.8		497.0
Other	12.5		—		—		12.5
Total retail	625.5		431.7		11.3		1,068.5
Wholesale	57.3		—		—		57.3
Transmission	13.4		—		—		13.4
Other	11.6		31.6		—		43.2
Total revenue from contracts with customers	707.8		463.3		11.3		1,182.4
Alternative revenue and other	33.7		5.8		1.1		40.6
Total revenues	$	741.5	$	469.1	$	12.4	$	1,223.0



	Three Months Ended March 31, 2018
(Millions of Dollars)	Electric		Natural Gas		All Other		Total
Major revenue types
Revenue from contracts with customers:
Residential	$	227.6	$	227.8	$	2.7	$	458.1
C&I	343.2		86.0		7.2		436.4
Other	12.2		—		—		12.2
Total retail	583.0		313.8		9.9		906.7
Wholesale	47.9		—		—		47.9
Transmission	12.3		—		—		12.3
Other	18.8		24.9		—		43.7
Total revenue from contracts with customers	662.0		338.7		9.9		1,010.6
Alternative revenue and other	36.3		25.3		1.1		62.7
Total revenues	$	698.3	$	364.0	$	11.0	$	1,073.3


6.	Income Taxes

Except to the extent noted below, Note 8 to the consolidated financial statements included in PSCo’s Annual Report on Form 10-K for the year ended Dec. 31, 2018 appropriately represents, in all material respects, the current status of other income tax matters, and are incorporated herein by reference.



	Three Months Ended March 31
	2019		2018
Federal statutory rate	21.0	%	21.0	%
State tax (net of federal tax effect)	3.7		3.7
Increases (decreases) in tax from:
Wind PTCs	(7.5	)	—
Regulatory differences ^(a)	(3.9	)	(1.5	)
Other tax credits and allowances (net)	(1.2	)	(1.0	)
Other (net)	—		0.4
Effective income tax rate	12.1	%	22.6	%

^(a)

Regulatory differences for income tax purposes primarily include the ARAM, ARAM deferral and AFUDC - Equity. ARAM is a method to flow back excess deferred taxes to customers. ARAM has been deferred when regulatory treatment has not been established. As Xcel Energy received direction from its regulatory commissions regarding the return of excess deferred taxes to customers, the ARAM deferral was reversed. This resulted in a reduction to tax expense with a corresponding reduction to revenue.

Federal Audits— PSCO is a member of the Xcel Energy affiliated group that files a consolidated federal income tax return. Statute of limitations applicable to Xcel Energy’s federal income tax returns expire as follows:



Tax Year(s)		Expiration
2009 - 2013		October 2019
2014 - 2016		September 2020
2017		September 2021

In the third quarter of 2015, the IRS commenced an examination of tax years 2012 and 2013. In the third quarter of 2017, the IRS concluded the audit of tax years 2012 and 2013 and proposed an adjustment that would impact Xcel Energy’s NOL and ETR. Xcel Energy filed a protest with the IRS. As of March 31, 2019, the case has been forwarded to Office of Appeals and Xcel Energy has recognized its best estimate of income tax expense that will result from a final resolution of this issue; however, the outcome and timing of a resolution is unknown.

In the fourth quarter of 2018, the IRS began an audit of tax years 2014 - 2016. As of March 31, 2019 no adjustments have been proposed.

State Audits — PSCo is a member of the Xcel Energy affiliated group that files consolidated state income tax returns. As of March 31, 2019, PSCo’s earliest open tax year that is subject to examination by state taxing authorities under applicable statutes of limitations is 2009. There are currently no state income tax audits in progress.

Unrecognized Benefits — Unrecognized tax benefit balance includes permanent tax positions, which if recognized would affect the annual ETR. In addition, the unrecognized tax benefit balance includes temporary tax positions for which the ultimate deductibility is highly certain, but for which there is uncertainty about the timing of such deductibility. A change in the period of deductibility would not affect the ETR but would accelerate the payment to the taxing authority to an earlier period.

Unrecognized tax benefits - permanent vs temporary:



(Millions of Dollars)	March 31, 2019		Dec. 31, 2018
Unrecognized tax benefit — Permanent tax positions	$	5.7	$	5.4
Unrecognized tax benefit — Temporary tax positions	4.8		4.9
Total unrecognized tax benefit	$	10.5	$	10.3

Unrecognized tax benefits were reduced by tax benefits associated with NOL and tax credit carryforwards:



(Millions of Dollars)	March 31, 2019			Dec. 31, 2018
NOL and tax credit carryforwards	$	(6.5	)	$	(5.6	)

Net deferred tax liability associated with the unrecognized tax benefit amounts and related NOLs and tax credits carryforwards were $3.0 million and $2.0 million for March 31, 2019 and Dec. 31, 2018, respectively.

As the IRS Appeals and federal audit progress and state audits resume, it is reasonably possible that the amount of unrecognized tax benefit could decrease up to approximately $8.7 million in the next 12 months.

Payable for interest related to unrecognized tax benefits is partially offset by the interest benefit associated with NOL and tax credit carryforwards.

Interest payable related to unrecognized tax benefits:



(Millions of Dollars)	March 31, 2019			Dec. 31, 2018
Payable for interest related to unrecognized tax benefits at beginning of period	$	(0.7	)	$	(0.3	)
Interest expense related to unrecognized tax benefits	(0.1		)	(0.4		)
Payable for interest related to unrecognized tax benefits at end of period	$	(0.8	)	$	(0.7	)

No amounts were accrued for penalties related to unrecognized tax benefits as of March 31, 2019 or Dec. 31, 2018.


7.	Fair Value of Financial Assets and Liabilities

Fair Value Measurements

The accounting guidance for fair value measurements and disclosures provides a single definition of fair value and requires ~~certain~~ disclosures about assets and liabilities measured at fair value. A hierarchical framework for disclosing the observability of the inputs utilized in measuring assets and liabilities at fair value is established by this guidance. ~~The three levels in the hierarchy are as follows:~~

Level 1 — Quoted prices are available in active markets for identical assets or liabilities as of the reporting date. The types of assets and liabilities included in Level 1 are highly liquid and actively traded instruments with quoted prices.

Level 2 — Pricing inputs are other than quoted prices in active markets, but are either directly or indirectly observable as of the reporting date. The types of assets and liabilities included in Level 2 are typically either comparable to actively traded securities or contracts, or priced with models using highly observable inputs.

Level 3 — Significant inputs to pricing have little or no observability as of the reporting date. The types of assets and liabilities included in Level 3 are those valued with models requiring significant management judgment or estimation.

Specific valuation methods ~~include the following:~~

include:

Cash equivalents — The fair values of cash equivalents are generally based on cost plus accrued interest; money market funds are measured using quoted net asset value.

Interest rate derivatives — The fair values of interest rate derivatives are based on broker quotes that utilize current market interest rate forecasts.

Commodity derivatives — The methods used to measure the fair value of commodity derivative forwards and options generally utilize observable forward prices and volatilities, as well as observable pricing adjustments for specific delivery locations, and are generally assigned a Level 2 classification. When contractual settlements relate to delivery locations for which pricing is relatively unobservable, or extend to periods beyond those readily observable on active exchanges or quoted by brokers, the significance of the use of less observable ~~forecasts of long-term forward prices and volatilities~~inputs on a valuation is evaluated, and may result in Level 3 classification.

Derivative Instruments Fair Value Measurements

PSCo enters into derivative instruments, including forward contracts, futures, swaps and options, for trading purposes and to manage risk in connection with changes in interest rates, utility commodity prices and vehicle fuel prices.

Interest Rate Derivatives —— PSCo enters into various instruments that effectively fix the interest payments on certain floating rate debt obligations or effectively fix the yield or price on a specified benchmark interest rate for an anticipated debt issuance for a specific period. These derivative instruments are generally designated as cash flow hedges for accounting purposes.

At March 31, ~~2018,~~2019, accumulated other comprehensive losses related to interest rate derivatives included $1.2 million of net losses expected to be reclassified into earnings during the next 12 months as the related hedged interest rate transactions impact earnings, including forecasted amounts for unsettled hedges, as applicable.

Wholesale and Commodity Trading Risk — PSCo conducts various wholesale and commodity trading activities, including the purchase and sale of electric capacity, energy, energy-related instruments and natural ~~gas related~~gas-related instruments, including derivatives. ~~PSCo’s risk management policy allows management~~PSCo is allowed to conduct these activities within guidelines and limitations as approved by its risk management committee, ~~which is made up~~comprised of management personnel not directly involved in ~~the~~ activities governed by this policy.

Commodity Derivatives —— PSCo enters into derivative instruments to manage variability of future cash flows from changes in commodity prices in its electric and natural gas operations, as well as for trading purposes. This could include the purchase or sale of energy or energy-related products, natural gas to generate electric energy, natural gas for resale, and vehicle fuel.

PSCo ~~enters~~may enter into derivative instruments that mitigate commodity price risk on behalf of electric and natural gas customers but may not be designated as qualifying hedging transactions. Changes in the fair value of non-trading commodity derivative instruments are recorded in other comprehensive income or deferred as a regulatory asset or liability. The classification as a regulatory asset or liability is based on commission approved regulatory recovery mechanisms.

As of March 31, 2019, PSCo had no ~~income related to the ineffectiveness of~~commodity contracts designated as cash flow hedges, ~~for~~and there were no net gains related to commodity derivative cash flow hedges recorded as a component of accumulated other comprehensive losses or related amounts expected to be reclassified into earnings during the ~~three months ended March 31, 2018 and 2017.~~next 12 months.

~~Additionally,~~

PSCo also enters into commodity derivative instruments for trading purposes not directly related to commodity price risks associated with serving its electric and natural gas customers. Changes in the fair value of these commodity derivatives are recorded in electric operating revenues, net of amounts credited to customers under margin-sharing mechanisms.

~~The following table details the gross~~Gross notional amounts of commodity forwards and ~~options at March 31, 2018 and Dec. 31, 2017:~~options:


(Amounts in Thousands) ^(a)(b)	March 31, 2018	Dec. 31, 2017
(Amounts in Millions) ^(a)(b)			March 31, 2019	Dec. 31, 2018
Megawatt hours of electricity	21,657	22,260	17.7	24.4
Million British thermal units of natural gas	11,780	13,410	26.0	48.4


^(a)	Amounts are not reflective of net positions in the underlying commodities.


^(b)	Notional amounts for options are included on a gross basis, but are weighted for the probability of exercise.

Consideration of Credit Risk and Concentrations — PSCo continuously monitors the creditworthiness of the counterparties to its interest rate derivatives and commodity derivative contracts prior to settlement, and assesses each counterparty’s ability to perform on the transactions set forth in the contracts. The ~~following tables detail the~~ impact of ~~derivative activity during~~credit risk was immaterial to the ~~three months ended~~fair value of unsettled commodity derivatives presented in the consolidated balance sheets. PSCo’s most significant concentrations of credit risk with particular entities or industries are contracts with counterparties to its wholesale, trading and non-trading commodity activities.

At March 31, ~~2018 and 2017~~2019, six of PSCo’s 10 most significant counterparties for these activities, comprising $54.9 million or 57% of this credit exposure, had investment grade credit ratings from S&P Global Ratings, Moody’s Investor Services or Fitch Ratings. Four of the 10 most significant counterparties, comprising $16.9 million or 17% of this credit exposure, were not rated by these external agencies, but based on ~~accumulated~~PSCo’s internal analysis, had credit quality consistent with investment grade. Eight of these significant counterparties are municipal or cooperative electric entities, or other ~~comprehensive loss, regulatory assets and liabilities, and income:~~

utilities.

Three Months Ended March 31, 2018

Pre-Tax Fair Value
Losses Recognized
During the Period in:

Pre-Tax Losses
Reclassified into Income
During the Period from:

(Thousands of Dollars)
Accumulated
Other
Comprehensive
Loss

Regulatory
(Assets) and
Liabilities

Accumulated
Other
Comprehensive
Loss

Regulatory
Assets and
(Liabilities)

Pre-Tax Gains (Losses)
Recognized
During the Period
in Income

Derivatives designated as cash flow hedges
Interest rate $ —
$ —
$ 398
^(a)
$ —
$ —

Total $ —
$ —
$ 398
$ —
$ —

Other derivative instruments
Commodity trading $ —
$ —
$ —
$ —
$ 524
^(b)
Natural gas commodity —
(171 ) —
2,749
^(c)
(1,581 )
^(c)
Total $ —
$ (171 ) $ —
$ 2,749
$ (1,057 )
Impact of derivative activity:



	Pre-Tax Fair Value Gains (Losses) Recognized During the Period in:
(Millions of Dollars)	Accumulated Other Comprehensive Loss		Regulatory(Assets) and Liabilities
Three Months Ended March 31, 2019
Other derivative instruments
Natural gas commodity	$	—	$	3.3
Total	$	—	$	3.3

Three Months Ended March 31, 2018
Other derivative instruments
Natural gas commodity	$	—	$	(0.2	)
Total	$	—	$	(0.2	)

Three Months Ended March 31, 2017

Pre-Tax Fair Value
Losses Recognized
During the Period in:

Pre-Tax Losses
Reclassified into Income
During the Period from:

(Thousands of Dollars)
Accumulated
Other
Comprehensive
Loss

Regulatory
(Assets) and
Liabilities

Accumulated
Other
Comprehensive
Loss

Regulatory
Assets and
(Liabilities)

Pre-Tax Gains (Losses)
Recognized
During the Period
in Income

Derivatives designated as cash flow hedges
Interest rate $ —
$ —
$ 398
^(a)
$ —
$ —

Total $ —
$ —
$ 398
$ —
$ —

Other derivative instruments
Commodity trading $ —
$ —
$ —
$ —
$ 379
^(b)
Natural gas commodity —
(5,387 ) —
282
^(c)
(2,990 )
^(c)
Total $ —
$ (5,387 ) $ —
$ 282
$ (2,611 )



	Pre-Tax (Gains) Losses Reclassified into Income During the Period from:
(Millions of Dollars)	Accumulated Other Comprehensive Loss			Regulatory Assets and (Liabilities)				Pre-Tax Gains (Losses) Recognized During the Period in Income
Three Months Ended March 31, 2019
Derivatives designated as cash flow hedges
Interest rate	$	0.4	^(a)	$	—			$	—
Total	$	0.4		$	—			$	—
Other derivative instruments
Commodity trading	$	—		$	—			$	0.9		^(b)
Natural gas commodity	—			(1.3		)	^(c)	(2.0		)	^(c)
Total	$	—		$	(1.3	)		$	(1.1	)

Three Months Ended March 31, 2018
Derivatives designated as cash flow hedges
Interest rate	$	0.4	^(a)	$	—			$	—
Total	$	0.4		$	—			$	—
Other derivative instruments
Commodity trading	$	—		$	—			$	0.5		^(b)
Natural gas commodity	—			2.7			^(c)	(1.6		)	^(c)
Total	$	—		$	2.7			$	(1.1	)


^(a)	Amounts are recorded to interest charges.


^(b)	Amounts are recorded to interest charges. Amounts are recorded to electric operating revenues. Portions of these gains and losses are subject to sharing with electric customers through margin-sharing mechanisms and deducted from gross revenue as appropriate.

^(c)

~~Certain~~Amounts for the three months ended March 31, 2019 and 2018 included no settlement gain or losses and $1.2 million of settlement losses, respectively, on derivatives ~~are utilized~~entered to mitigate natural gas price risk for electric generation ~~and are~~ recorded to electric fuel and purchased power, subject to cost-recovery mechanisms and reclassified to a regulatory asset, as appropriate. ~~Amounts for the three months ended March 31, 2018 and 2017 included $1.2 million of settlement losses and $0.9 million of settlement gains, respectively. The remaining~~Remaining derivative settlement ~~gains and~~ losses for the three months ended March 31, ~~2018~~2019 and ~~2017~~2018 relate to natural gas operations and are recorded to cost of natural gas sold and transported. ~~These gains and losses~~Losses are subject to cost-recovery mechanisms and reclassified out of income to a regulatory asset, ~~or liability,~~ as appropriate.

PSCo had no derivative instruments designated as fair value hedges during the three months ended March 31, ~~2018~~2019 and ~~2017. Therefore, no gains or losses from fair value hedges or related hedged transactions were recognized for these periods.~~

~~Consideration of Credit Risk and Concentrations —~~ PSCo continuously monitors the creditworthiness of the counterparties to its interest rate derivatives and commodity derivative contracts prior to settlement, and assesses each counterparty’s ability to perform on the transactions set forth in the contracts. Given this assessment, as well as an assessment of the impact of PSCo’s own credit risk when determining the fair value of derivative liabilities, the impact of credit risk was immaterial to the fair value of unsettled commodity derivatives presented in the consolidated balance sheets.

PSCo employs additional credit risk control mechanisms when appropriate, such as letters of credit, parental guarantees, standardized master netting agreements and termination provisions that allow for offsetting of positive and negative exposures. Credit exposure is monitored and, when necessary, the activity with a specific counterparty is limited until credit enhancement is provided.

PSCo’s most significant concentrations of credit risk with particular entities or industries are contracts with counterparties to its wholesale, trading and non-trading commodity activities. At March 31, 2018, four of PSCo’s 10 most significant counterparties for these activities, comprising $9.8 million or 14 percent of this credit exposure, had investment grade credit ratings from Standard & Poor’s, Moody’s or Fitch Ratings. Five of the 10 most significant counterparties, comprising $22.4 million or 31 percent of this credit exposure, were not rated by these external agencies, but based on PSCo’s internal analysis, had credit quality consistent with investment grade. The one remaining significant counterparty, comprising $21.2 million or 29 percent of this credit exposure, had credit quality less than investment grade, based on ratings from external analysis. Nine of these significant counterparties are municipal or cooperative electric entities, or other utilities.

2018.

Credit Related Contingent Features— Contract provisions for derivative instruments that PSCo enters into, including those accounted for as normal purchase-normal sale contracts and therefore not reflected on the consolidated balance ~~sheet,~~sheets, may require the posting of collateral or settlement of the contracts for various reasons, including if PSCo’s credit ratings are downgraded below its investment grade credit rating by any of the major credit rating agencies, or for cross-default contractual provisions ~~that could result in the settlement of such contracts~~ if there was a failure under other financing arrangements related to payment terms or other covenants. At March 31, ~~2018~~2019 and Dec. 31, ~~2017,~~2018, there were no derivative instruments in a ~~material~~ liability position with such underlying contract provisions.

Certain derivative instruments are also subject to contract provisions that contain adequate assurance clauses. These provisions allow counterparties to seek performance assurance, including cash collateral, in the event that PSCo’s ability to fulfill its contractual obligations is reasonably expected to be impaired. PSCo had no collateral posted related to adequate assurance clauses in derivative contracts as of March 31, ~~2018~~2019 and Dec. 31, ~~2017.~~2018.

Recurring Fair Value Measurements— ~~The following table presents, for each of the fair value hierarchy levels,~~ PSCo’s assets and liabilities measured at fair value on a recurring ~~basis at March 31, 2018:~~basis:



	March 31, 2019													Dec. 31, 2018
	Fair Value						Fair Value Total		Netting ^(a)					Fair Value						Fair Value Total		Netting ^(a)
(Millions of Dollars)	Level 1		Level 2		Level 3		Fair Value Total		Netting ^(a)			Total		Level 1		Level 2		Level 3		Fair Value Total		Netting ^(a)			Total
Current derivative assets
Other derivative instruments:
Commodity trading	$	0.7	$	48.9	$	—	$	49.6	$	(19.5	)	$	30.1	$	2.3	$	65.0	$	0.1	$	67.4	$	(28.2	)	$	39.2
Natural gas commodity	—		—		—		—		—			—		—		3.4		—		3.4		—			3.4
Total current derivative assets	$	0.7	$	48.9	$	—	$	49.6	$	(19.5	)	30.1		$	2.3	$	68.4	$	0.1	$	70.8	$	(28.2	)	42.6
PPAs ^(b)												—													—
Current derivative instruments												$	30.1												$	42.6
Noncurrent derivative assets
Other derivative instruments:
Commodity trading	$	—	$	3.5	$	—	$	3.5	$	(0.9	)	$	2.6	$	—	$	1.6	$	—	$	1.6	$	(0.4	)	$	1.2
Total noncurrent derivative assets	$	—	$	3.5	$	—	$	3.5	$	(0.9	)	2.6		$	—	$	1.6	$	—	$	1.6	$	(0.4	)	1.2
PPAs ^(b)												—													—
Noncurrent derivative instruments												$	2.6												$	1.2


	March 31, 2018														March 31, 2019															Dec. 31, 2018
	Fair Value						Fair Value Total			Counterparty Netting ^(b)					Fair Value						Fair Value Total			Netting ^(a)						Fair Value									Fair Value Total			Netting ^(a)
(Thousands of Dollars)	Level 1		Level 2		Level 3				Total																														Fair Value Total			Netting ^(a)
Current derivative assets							Fair Value Total
Other derivative instruments:										Counterparty Netting ^(b)
Commodity trading	$	587	$	7,965	$	2	$	8,554		$	(5,373	)	$	3,181
Total current derivative assets	$	587	$	7,965	$	2	$	8,554		$	(5,373	)	3,181
PPAs ^(a)													1,716
Current derivative instruments													$	4,897
Noncurrent derivative assets
Other derivative instruments:
Commodity trading	$	—	$	2,298	$	—	$	2,298		$	(1,236	)	$	1,062
Total noncurrent derivative assets	$	—	$	2,298	$	—	$	2,298		$	(1,236	)	1,062
PPAs ^(a)													31
Noncurrent derivative instruments													$	1,093
(Millions of Dollars)															Level 1		Level 2		Level 3		Fair Value Total		Fair Value Total				Netting ^(a)			Total			Level 1			Level 2			Level 3			Fair Value Total				Netting ^(a)			Total
Current derivative liabilities																																										Fair Value Total				Netting ^(a)
Other derivative instruments:																							Fair Value Total
Commodity trading	$	457	$	7,528	$	1	$	7,986		$	(5,372	)	$	2,614	$	0.9	$	48.0	$	0.1	$	49.0		$	(30.2	)	Netting ^(a)	$	18.8		$	2.4		$	64.2		$	—		$	66.6		$	(34.7	)		$	31.9
Total current derivative liabilities	$	457	$	7,528	$	1	$	7,986		$	(5,372	)	2,614		$	0.9	$	48.0	$	0.1	$	49.0		$	(30.2	)	18.8			$	2.4		$	64.2		$	—		$	66.6		$	(34.7	)		31.9
PPAs ^(a)													4,730
PPAs ^(b)																											1.4																			2.7
Current derivative instruments													$	7,344													$	20.2																		$	34.6
Noncurrent derivative liabilities
Other derivative instruments:
Commodity trading	$	—	$	2,224	$	—	$	2,224		$	(1,236	)	$	988	$	—	$	1.9	$	—	$	1.9		$	(0.8	)	$	1.1		$	—		$	1.1		$	—		$	1.1		$	(0.5	)		$	0.6
Total noncurrent derivative liabilities	$	—	$	2,224	$	—	$	2,224		$	(1,236	)	988		$	—	$	1.9	$	—	$	1.9		$	(0.8	)	1.1			$	—		$	1.1		$	—		$	1.1		$	(0.5	)		0.6
PPAs ^(a)													1,379
PPAs ^(b)																											—																			—
Noncurrent derivative instruments													$	2,367													$	1.1																		$	0.6

^(a)

PSCo nets derivative instruments and related collateral in its consolidated balance sheet when supported by a legally enforceable master netting agreement, and all derivative instruments and related collateral amounts were subject to master netting agreements at March 31, 2019 and Dec. 31, 2018. At both March 31, 2019 and Dec. 31, 2018, derivative assets and liabilities include no obligations to return cash collateral. At March 31, 2019 and Dec. 31, 2018, derivative assets and liabilities include the rights to reclaim cash collateral of $10.7 million and $6.5 million, respectively. The counterparty netting amounts presented exclude settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements.


^(b)	During 2006, PSCo qualified these contracts under the normal purchase exception. Based onthis qualification, the contracts are no longer adjusted to fair value and the previous carrying value of these contracts will be amortized over the remaining contract lives along with the offsetting regulatory assets and liabilities.

^(b)

PSCo nets derivative instruments and related collateral in its consolidated balance sheet when supported by a legally enforceable master netting agreement, and all derivative instruments and related collateral amounts were subject to master netting agreements at March 31, 2018. At March 31, 2018, derivative assets and liabilities include no obligations to return cash collateral or rights to reclaim cash collateral. The counterparty netting amounts presented exclude settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements.

~~The following table presents, for each of the fair value hierarchy levels, PSCo’s assets and liabilities measured at fair value on a recurring basis at Dec. 31, 2017:~~

Dec. 31, 2017
Fair Value
Fair Value
Total

Counterparty
Netting ^(b)

(Thousands of Dollars) Level 1 Level 2 Level 3 Total
Current derivative assets
Other derivative instruments:
Commodity trading $ 528
$ 4,488
$ 12
$ 5,028
$ (3,554 ) $ 1,474
Natural gas commodity —
18
—
18
(10 ) 8
Total current derivative assets $ 528
$ 4,506
$ 12
$ 5,046
$ (3,564 ) 1,482
1,715
Current derivative instruments $ 3,197
Noncurrent derivative assets
Other derivative instruments:

Commodity trading $ —
$ 1,541
$ —
$ 1,541
$ (563 ) $ 978
Total noncurrent derivative assets $ —
$ 1,541
$ —
$ 1,541
$ (563 ) 978
PPAs ^(a)
31
Noncurrent derivative instruments $ 1,009
Current derivative liabilities
Other derivative instruments:
Commodity trading $ 446
$ 4,285
$ 6
$ 4,737
$ (3,431 ) $ 1,306
Natural gas commodity —
1,016
—
1,016
(10 ) 1,006
Total current derivative liabilities $ 446
$ 5,301
$ 6
$ 5,753
$ (3,441 ) 2,312
PPAs ^(a)
5,036
Current derivative instruments $ 7,348
Noncurrent derivative liabilities
Other derivative instruments:

Commodity trading $ —
$ 1,362
$ —
$ 1,362
$ (563 ) $ 799
Total noncurrent derivative liabilities $ —
$ 1,362
$ —
$ 1,362
$ (563 ) 799
PPAs ^(a)
$ 2,669
Noncurrent derivative instruments $ 3,468


^(a)	During 2006, PSCo qualified these contracts under the normal purchase exception. Based on this qualification, the contracts are no longer adjusted to fair value and the previous carrying value of these contracts will be amortized over the remaining contract lives along with the offsetting regulatory assets and liabilities.

^(b)

PSCo nets derivative instruments and related collateral in its consolidated balance sheet when supported by a legally enforceable master netting agreement, and all derivative instruments and related collateral amounts were subject to master netting agreements at Dec. 31, 2017. At Dec. 31, 2017, derivative assets and liabilities include no obligations to return cash collateral or rights to reclaim cash collateral. The counterparty netting amounts presented exclude settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements.

There were ~~immaterial~~$0.7 million of gains and immaterial losses recognized in earnings for Level 3 commodity trading derivatives in the three months ended March 31, 2019 and 2018, ~~and 2017.~~

respectively.

PSCo recognizes transfers between fair value hierarchy levels as of the beginning of each period. There were no transfers of amounts between levels for derivative instruments for the three months ended March 31, ~~2018~~2019 and ~~2017.~~2018.

Fair Value of Long-Term Debt

~~As of March 31, 2018 and Dec. 31, 2017, other~~Other financial instruments for which the carrying amount did not equal fair ~~value were as follows:~~value:


	March 31, 2018				Dec. 31, 2017				March 31, 2019				Dec. 31, 2018
(Thousands of Dollars)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
(Millions of Dollars)									Carrying Amount		Fair Value		Carrying Amount		Fair Value
Long-term debt, including current portion	$	4,607,825	$	4,845,116	$	4,608,275	$	5,024,840	$	4,846.1	$	5,162.2	$	4,997.6	$	5,123.2

~~The fair~~Fair value of PSCo’s long-term debt is estimated based on recent trades and observable spreads from benchmark interest rates for similar securities. ~~The fair~~Fair value estimates are based on information available to management as of March 31, ~~2018~~2019 and Dec. 31, ~~2017,~~2018, and given the observability of the inputs, ~~to these estimates,~~ the fair values presented for long-term debt ~~have been~~were assigned aas Level 2.


8.	Benefit Plans and Other Postretirement Benefits

Components of Net Periodic Benefit Cost (Credit)



	Three Months Ended March 31
	2019			2018			2019			2018
(Millions of Dollars)	Pension Benefits						Postretirement Health Care Benefits
Service cost	$	6.4		$	7.2		$	0.1		$	0.1
Interest cost ^(a)	12.9			11.8			3.9			3.8
Expected return on plan assets ^(a)	(17.1		)	(17.1		)	(4.7		)	(5.7		)
Amortization of prior service credit ^(a)	(0.8		)	(0.8		)	(1.4		)	(1.5		)
Amortization of net loss ^(a)	6.3			7.8			0.7			1.0
Net periodic benefit cost (credit)	7.7			8.9			(1.4		)	(2.3		)
Credits not recognized due to the effects of regulation	1.9			1.5			0.3			—
Net benefit cost (credit) recognized for financial reporting	$	9.6		$	10.4		$	(1.1	)	$	(2.3	)


^(a)	The components of net periodic cost other than the service cost component are included in the line item “other income, net” in the consolidated statement of income or capitalized on the consolidated balance sheet as a regulatory asset.

In January 2019, contributions of $150 million were made across four of Xcel Energy’s pension plans, of which $43 million was attributable to PSCo. Xcel Energy does not expect additional pension contributions during 2019.


9.	~~Other Income, Net~~Commitments and Contingencies

Legal Contingencies

~~Other income, net consisted~~PSCo is involved in various litigation matters that are being defended and handled in the ordinary course of business. The assessment of whether a loss is probable or is a reasonable possibility, and whether the loss or a range of loss is estimable, often involves complex judgments about future events. Management maintains accruals for losses that are probable of being incurred and subject to reasonable estimation.

Management is sometimes unable to estimate an amount or range of a reasonably possible loss in certain situations, including when (1) the damages sought are indeterminate, (2) the proceedings are in the early stages, or (3) the matters involve novel or unsettled legal theories. In such cases, there is considerable uncertainty regarding the timing or ultimate resolution of such matters, including a possible eventual loss. For current proceedings not specifically reported herein, management does not anticipate that the ultimate liabilities, if any, arising from such current proceedings would have a material effect on PSCo’s financial statements. Unless otherwise required by GAAP, legal fees are expensed as incurred.

Employment, Tort and Commercial Litigation

Line Extension Disputes — In December 2015, the DRC filed a lawsuit seeking monetary damages in the Denver District Court, stating PSCo failed to award proper allowances and refunds for line extensions to new developments pursuant to the terms of electric and gas service agreements. The dispute involves claims by over fifty developers. In February 2018, the Colorado Supreme Court denied DRC’s petition to appeal the Denver District Court’s dismissal of the ~~following:~~lawsuit, effectively terminating this litigation. However, in January 2018, DRC filed a new lawsuit in Boulder County District Court, asserting a single claim that PSCo was required to file its line extension agreements with the CPUC but failed to do so.

This claim is substantially similar to the arguments previously raised by DRC. PSCo filed a motion to dismiss this claim, which was granted in May 2018. DRC subsequently filed an appeal to the Colorado Court of Appeals with its opening brief in January 2019 and PSCo filed its answer brief in February 2019. DRC’s Answer-Reply Brief was filed March 18, 2019. PSCo filed a limited final Reply Brief on April 8, 2019 and the DRC subsequently requested an oral argument. It is uncertain when a decision will be rendered.

PSCo has concluded that a loss is remote with respect to both of these matters as the service agreements were developed to implement CPUC approved tariffs and PSCo has complied with the tariff provisions. If a loss were sustained, PSCo believes it would be allowed to recover costs through traditional regulatory mechanisms. Amount or range in dispute is presently unknown and no accrual has been recorded for this matter.

Environmental

MGP, Landfill or Disposal Sites — PSCo is currently investigating or remediating threeMGP, landfill or other disposal sites across its service territories, and these activities will continue through at least 2020. PSCo accrued $0.9 million and $0.6 million as of March 31, 2019 and Dec. 31, 2018, respectively, for these sites. There may be insurance recovery and/or recovery from other potentially responsible parties, offsetting a portion of the costs incurred.

Environmental Requirements — Water and Waste

Coal Ash Regulation— PSCo’s operations are subject to federal and state laws that impose requirements for handling, storage, treatment and disposal of solid waste. In 2015, the EPA published the CCR Rule. Litigation was brought challenging the rule in the United States Court of Appeals for the District of Columbia Circuit.

Under the CCR Rule, utilities are required to complete groundwater sampling around their CCR landfills and surface impoundments. PSCo has identified two sites where a statistically significant increase of certain constituents exists in the groundwater near landfills and/or impoundments. The groundwater monitored at those two sites is directly adjacent to the CCR units and does not indicate any impact to local drinking water. PSCo has completed removal of CCR from these impoundments and plans to close these landfills. By the end of 2019, only six of PSCo’s regulated ash units are expected to be in operation. PSCo is conducting additional groundwater sampling, initiating the assessment of corrective measures as required by the CCR Rule, and will evaluate whether corrective action is required at any CCR landfills or surface impoundments.

Until PSCo completes its assessment, it is uncertain what impact, if any, there will be on the operations, financial condition or cash flows.

Leases

PSCo evaluates a variety of contracts that may contain leases, including PPAs and arrangements for the use of office space and other facilities, vehicles and equipment. Under ASC Topic 842, adopted by PSCo on Jan. 1, 2019, a contract contains a lease if it conveys the exclusive right to control the use of a specific asset. A contract determined to contain a lease is evaluated further to determine if the arrangement is a finance lease.

ROU assets represent PSCo's rights to use leased assets. Starting in 2019, the present value of future operating lease payments are recognized in other current liabilities and noncurrent operating lease liabilities. These amounts, adjusted for any prepayments or incentives, are recognized as operating lease ROU assets.

Most of PSCo’s leases do not contain a readily determinable discount rate, and therefore the present value of future lease payments is calculated using the estimated incremental borrowing rate for similar borrowing periods (weighted-average of 4.1%). PSCo has elected to utilize the practical expedient under which non-lease components, such as asset maintenance costs included in payments to the lessor, are not deducted from minimum lease payments for the purposes of lease accounting and disclosure.

Leases with an initial term of 12 months or less are classified as short-term leases and are not recognized on the consolidated balance sheet.

Operating lease ROU assets:

Three Months Ended March 31
(Thousands of Dollars) 2018 2017
Other nonoperating income $ 482
$ 3,431

Interest (expense) income (136 ) 375

Insurance policy expense (77 ) (79 )
Benefits non-service cost (29 ) (513 )
Other nonoperating expense (9 ) (10 )
Other income, net $ 231
$ 3,204



(Millions of Dollars)	March 31, 2019
PPAs	$	585.1
Other	67.7
Gross operating lease ROU assets	652.8
Accumulated amortization	(19.8		)
Net operating lease ROU assets	$	633.0

In 2019, ROU assets for finance leases are included in other noncurrent assets, and the present value of future finance lease payments are included in other current liabilities and other noncurrent liabilities. Prior to 2019, finance leases were included in property, plant and equipment, the current portion of long-term debt and long-term debt.

PSCo’s most significant finance lease activities are related to WYCO.WYCO is a joint venture with CIG to develop and lease natural gas pipeline, storage and compression facilities. Xcel Energy Inc. has a 50% ownership interest in WYCO. WYCO leases its facilities to CIG, and CIG operates the facilities, providing natural gas storage and transportation services to PSCo under separate service agreements.

PSCo accounts for its Totem natural gas storage service and Front Range pipeline arrangements with CIG and WYCO, respectively, as finance leases. Xcel Energy Inc. eliminates 50% of the finance lease obligation related to WYCO in the consolidated balance sheet along with an equal amount of Xcel Energy Inc.’s equity investment in WYCO.

Finance lease ROU assets:



(Millions of Dollars)	March 31, 2019
Gas storage facilities	$	200.5
Gas pipeline	20.7
Gross finance lease ROU assets	221.2
Accumulated amortization	(77.7		)
Net finance lease ROU assets	$	143.5

Given the impacts of accounting for regulated operations, and the resulting recognition of periodic expense at the amounts recovered in customer rates, cash expenditures for both operating and finance leases are consistent with recognized lease expense.

Components of lease expense:



(Millions of Dollars)	Three Months Ended March 31, 2019
Operating leases
PPA capacity payments	$	24.3
Other operating leases ^(a)	3.5
Total operating lease expense ^(b)	$	27.8

Finance leases
Amortization of ROU assets	$	1
Interest expense on lease liability	5
Total finance lease expense	$	6


^(a)	Includes short-term lease expense of $0.3 million.


^(b)	PPA capacity payments are included in electric fuel and purchased power on the consolidated statements of income. Expense for other operating leases is included in O&M expense and electric fuel and purchased power.

Future commitments under operating and finance leases as of March 31, 2019:



(Millions of Dollars)	PPA ^{(a) (b)} Operating Leases			Other Operating Leases			Total Operating Leases			Finance Leases
2019	$	71.6		$	9.6		$	81.2		$	18.7
2020	95.9			13.0			108.9			24.8
2021	96.4			12.0			108.4			23.6
2022	82.6			11.0			93.6			20.5
2023	70.0			10.9			80.9			20.3
Thereafter	288.6			29.2			317.8			420.4
Total minimum obligation	705.1			85.7			790.8			528.3
Interest component of obligation	(112.4		)	(14.5		)	(126.9		)	(384.8		)
Present value of minimum obligation	$	592.7		$	71.2		663.9			143.5
Less current portion							(82.8		)	(6.3		)
Noncurrent operating and finance lease liabilities							$	581.1		$	137.2

Weighted-average remaining lease term in years							8.3			39.2


^(a)	Amounts do not include PPAs accounted for as executory contracts and/or contingent payments, such as energy payments on renewable PPAs.


^(b)	PPA operating leases contractually expire at various dates through 2032.

Future commitments under operating and finance leases as of Dec. 31, 2018:



(Millions of Dollars)	PPA ^{(a) (b)} Operating Leases		Other Operating Leases		Total Operating Leases		Finance Leases
2019	$	95.5	$	10.8	$	106.3	$	24.9
2020	95.9		10.7		106.6		24.8
2021	96.4		9.5		105.9		23.6
2022	82.6		8.4		91.0		20.5
2023	70.0		8.1		78.1		20.3
Thereafter	288.6		53.4		342.0		420.4
Total minimum obligation							534.5
Interest component of obligation							(389.5		)
Present value of minimum obligation							$	145.0


^(a)	Amounts do not include PPAs accounted for as executory contracts and/or contingent payments, such as energy payments on renewable PPAs.


^(b)	PPA operating leases contractually expire at various dates through 2032.

Variable Interest Entities

Under certain PPAs, PSCo purchases power from IPPs for which PSCo is required to reimburse fuel costs, or to participate in tolling arrangements under which PSCo procures the natural gas required to produce the energy that it purchases. These specific PPAs create a variable interest in the associated IPP.

PSCo had approximately 1,571 MW of capacity under long-term PPAs as of March 31, 2019 and Dec. 31, 2018, with entities that have been determined to be VIEs. PSCo concluded that these entities are not required to be consolidated in its consolidated financial statements because it does not have the power to direct the activities that most significantly impact the entities’ economic performance. These agreements have expiration dates through 2032.


10.	Other Comprehensive Income (Loss)

Changes in accumulated other comprehensive loss, net of tax, for the three months ended March 31, 2019 and 2018:



	Three Months Ended March 31, 2019
(Millions of Dollars)	Gains and Losses on Cash Flow Hedges			Defined Benefit and Postretirement Items			Total
Accumulated other comprehensive loss at Jan. 1	$	(25.3	)	$	(0.2	)	$	(25.5	)
Losses reclassified from net accumulated other comprehensive loss
Interest rate derivatives (net of taxes of $0.1 and $0, respectively^(a)	0.3			—			0.3
Net current period other comprehensive income	0.3			—			0.3
Accumulated other comprehensive loss at March 31	$	(25.0	)	$	(0.2	)	$	(25.2	)



	Three Months Ended March 31, 2018
(Millions of Dollars)	Gains and Losses on Cash Flow Hedges			Defined Benefit and Postretirement Items			Total
Accumulated other comprehensive loss at Jan. 1	$	(26.5	)	$	(0.2	)	$	(26.7	)
Losses reclassified from net accumulated other comprehensive loss
Interest rate derivatives (net of taxes of $0.1 and $0, respectively^(a)	0.3			—			0.3
Net current period other comprehensive income	0.3			—			0.3
Accumulated other comprehensive loss at March 31	$	(26.2	)	$	(0.2	)	$	(26.4	)


^(a)	Included in interest charges.


11.	Segment Information

Operating results from the regulated electric utility and regulated natural gas utility are each separately and regularly reviewed by PSCo’s chief operating decision maker. PSCo evaluates performance based on profit or loss generated from the product or service provided. These segments are managed separately because the revenue streams are dependent upon regulated rate recovery, which is separately determined for each segment.

PSCo has the following reportable segments: regulated electric utility, regulated natural gas utility and all other.

~~PSCo’s~~Regulated Electric - The regulated electric utility segment generates ~~transmits~~electricity which is transmitted and ~~distributes electricity primarily~~distributed in ~~portions of~~ Colorado. ~~In addition, this~~This segment includes sales for resale and provides wholesale transmission service to various entities in the United States. Regulated electric utility also includes PSCo’s wholesale commodity and trading operations.

~~PSCo’s~~

Regulated Natural Gas - The regulated natural gas utility segment transports, stores and distributes natural gas ~~primarily~~ in portions of Colorado.

All Other - Revenues from operating segments not included above are below the necessary quantitative thresholds ~~and~~ are ~~therefore~~ included in the all other category. Those primarily include steam revenue, appliance repair services and nonutility real estate activities.

Asset and capital expenditure information is not provided for PSCo’s reportable segments because as an integrated electric and natural gas utility, PSCo operates significant assets that are not dedicated to a specific business segment, and reporting assets and capital expenditures by business segment would require arbitrary and potentially misleading allocations which may not necessarily reflect the assets that would be required for the operation of the business segments on a stand-alone basis.

~~To report income from operations for regulated electric and regulated natural gas utility segments, the majority of costs are directly assigned to each segment. However, some~~Certain costs, such as common depreciation, common O&M expenses and interest expense are allocated based on cost causation ~~allocators. A~~allocators across each segment. In addition, a general allocator is used for certain general and administrative expenses, including office supplies, rent, property insurance and general advertising.

(Thousands of Dollars) Regulated Electric Regulated Natural Gas All Other Reconciling Eliminations Consolidated Total
Three Months Ended March 31, 2018
Operating revenues ^(a)(b)
$ 698,274
$ 363,986
$ 11,038
$ —
$ 1,073,298
Intersegment revenues 112
64
—
(176 ) —
Total revenues $ 698,386
$ 364,050
$ 11,038
$ (176 ) $ 1,073,298
Net income $ 79,551
$ 53,712
$ 459
$ —
$ 133,722

(Thousands of Dollars) Regulated Electric Regulated Natural Gas All Other Reconciling Eliminations Consolidated Total
Three Months Ended March 31, 2017
Operating revenues ^(a)(b)
$ 711,388
$ 356,136
$ 13,010
$ —
$ 1,080,534
Intersegment revenues 92
56
—
(148 ) —
Total revenues $ 711,480
$ 356,192
$ 13,010
�� $ (148 ) $ 1,080,534
Net income (loss) $ 76,144
$ 34,483
$ 919
$ —
$ 111,546

^(a)~~Operating revenues include $1 million and $2 million of affiliate electric revenue~~PSCo’s segment information for the three months ended March ~~31, 2018 and 2017.~~

^(b)~~Operating revenues include $1 million of other affiliate revenue for the three months ended March 31, 2018 and 2017.~~


~~11.~~	~~Benefit Plans and Other Postretirement Benefits~~

~~Components of Net Periodic Benefit Cost (Credit)~~31:

Three Months Ended March 31
2018 2017 2018 2017
(Thousands of Dollars) Pension Benefits
Postretirement Health
Care Benefits
Service cost $ 7,271
$ 6,820
$ 152
$ 192
Interest cost ^(a)
11,814
12,640
3,749
4,191
Expected return on plan assets ^(a)
(17,130 ) (17,134 ) (5,675 ) (5,476 )
Amortization of prior service credit ^(a)
(845 ) (803 ) (1,545 ) (1,562 )
Amortization of net loss ^(a)
7,815
7,089
1,021
961
Net periodic benefit cost (credit) 8,925
8,612
(2,298 ) (1,694 )
Credits not recognized due to the effects of regulation 1,475
736
—
—
Net benefit cost (credit) recognized for financial reporting $ 10,400
$ 9,348
$ (2,298 ) $ (1,694 )


^(a)	The components of net periodic cost other than the service cost component are included in the line item “other income, net” in the income statement or capitalized on the balance sheet as a regulatory asset.

In January 2018, contributions of $150.0 million were made across four of Xcel Energy’s pension plans, of which $22.0 million was attributable to PSCo. Xcel Energy does not expect additional pension contributions during 2018.


~~12.~~	~~Other Comprehensive Income (Loss)~~

~~Changes in accumulated other comprehensive loss, net of tax, for the three months ended March 31, 2018 and 2017 were as follows:~~

Three Months Ended March 31, 2018
(Thousands of Dollars) Gains and Losses on Cash Flow Hedges Defined Benefit and Postretirement Items Total
Accumulated other comprehensive loss at Jan. 1 $ (26,465 ) $ (267 ) $ (26,732 )
Losses reclassified from net accumulated other comprehensive loss 300
2
302
Net current period other comprehensive income 300
2
302
Accumulated other comprehensive loss at March 31 $ (26,165 ) $ (265 ) $ (26,430 )

Three Months Ended March 31, 2017
(Thousands of Dollars) Gains and Losses on Cash Flow Hedges Defined Benefit and Postretirement Items Total
Accumulated other comprehensive loss at Jan. 1 $ (22,780 ) $ (220 ) $ (23,000 )
Losses reclassified from net accumulated other comprehensive loss 246
1
247
Net current period other comprehensive income 246
1
247
Accumulated other comprehensive loss at March 31 $ (22,534 ) $ (219 ) $ (22,753 )

~~Reclassifications from accumulated other comprehensive loss for the three months ended March 31, 2018 and 2017 were as follows:~~

Amounts Reclassified from Accumulated Other
Comprehensive Loss
(Thousands of Dollars) Three Months Ended March 31, 2018 Three Months Ended March 31, 2017
Losses on cash flow hedges:

Interest rate derivatives $ 398
^(a)
$ 398
^(a)
Total, pre-tax 398
398

Tax benefit (98 ) (152 )
Total, net of tax 300
246

Defined benefit pension and postretirement losses:
Amortization of net loss 2
^(b)
2
^(b)
Total, pre-tax 2
2

Tax benefit —
(1 )
Total, net of tax 2
1

Total amounts reclassified, net of tax $ 302
$ 247



(Millions of Dollars)	2019			2018
Regulated Electric
Operating revenues	$	741.5		$	698.3
Intersegment revenues	0.1			0.1
Total revenue	741.6			698.4
Net income	82.4			79.6
Regulated Natural Gas
Operating revenues	$	469.1		$	364.0
Intersegment revenues	0.1			0.1
Total revenue	469.2			364.1
Net income	59.2			53.7
All Other
Operating revenues^(a)	$	12.4		$	11.0
Intersegment revenues	—			—
Total revenue	12.4			11.0
Net income (loss)	(2.8		)	0.4
Consolidated Total
Operating revenues^(a)	$	1,223.2		$	1,073.5
Intersegment revenues	(0.2		)	(0.2		)
Total revenue	1,223.0			1,073.3
Net income	138.8			133.7


^(a)	~~Included in interest charges.~~Operating revenues include $1.1 million of other affiliate revenue for the three months ended March 31, 2019 and 2018.


^(b)	~~Included in the computation of net periodic pension and postretirement benefit costs. See Note 11 for details regarding these benefit plans.~~


~~13.~~	~~Revenues~~

PSCo principally generates revenue from the transmission, distribution and sale of electricity and the transportation, distribution and sale of natural gas to wholesale and retail customers. Performance obligations related to the sale of energy are satisfied as energy is delivered to customers. PSCo recognizes revenue in an amount that corresponds directly to the price of the energy delivered to the customer. The measurement of energy sales to customers is generally based on the reading of their meters, which occurs on a systematic basis throughout the month. At the end of each month, amounts of energy delivered to customers since the date of the last meter reading are estimated, and the corresponding unbilled revenue is recognized. Contract terms are generally short-term in nature, and as such PSCo does not recognize a separate financing component of its collections from customers. PSCo presents its revenues net of any excise or other fiduciary-type taxes or fees.

PSCo has various rate-adjustment mechanisms in place that provide for the recovery of natural gas, electric fuel and purchased energy costs. These cost-adjustment tariffs may increase or decrease the level of revenue collected from customers and are revised periodically for differences between the total amount collected under the clauses and the costs incurred. When applicable, under governing regulatory commission rate orders, fuel cost over-recoveries (the excess of fuel revenue billed to customers over fuel costs incurred) are deferred as regulatory liabilities and under-recoveries (the excess of fuel costs incurred over fuel revenues billed to customers) are deferred as regulatory assets.

Certain rate rider mechanisms qualify as alternative revenue programs under GAAP. These mechanisms arise from costs imposed upon the utility by action of a regulator or legislative body related to an environmental, public safety or other mandate. When certain criteria are met (including collection within 24 months), revenue is recognized equal to the revenue requirement, which may include return on rate base items and incentives. The mechanisms are revised periodically for differences between the total amount collected and the revenue recognized, which may increase or decrease the level of revenue collected from customers. Alternative revenue is recorded on a gross basis and is disclosed separate from revenue from contracts with customers in the period earned.

~~In the following tables, revenue is classified by the type of goods/services rendered and market/customer type. The tables also reconcile revenue to the reportable segments.~~

Three Months Ended March 31, 2018
(Thousands of Dollars) Regulated Electric Regulated Natural Gas All Other Total
Major revenue types
Revenue from contracts with customers:
Residential $ 227,649
$ 227,746
$ 2,696
$ 458,091
Commercial and industrial (C&I) 343,226
86,028
7,159
436,413
Other 12,176
—
60
12,236
Total retail 583,051
313,774
9,915
906,740
Wholesale 47,890
—
—
47,890
Transmission 12,252
—
—
12,252
Other 18,831
24,929
—
43,760
Total revenue from contracts with customers 662,024
338,703
9,915
1,010,642
Alternative revenue and other 36,250
25,283
1,123
62,656
Total revenues $ 698,274
$ 363,986
$ 11,038
$ 1,073,298

Three Months Ended March 31, 2017
(Thousands of Dollars) Regulated Electric Regulated Natural Gas All Other Total
Major revenue types
Revenue from contracts with customers:
Residential $ 234,434
$ 225,910
$ 2,564
$ 462,908
C&I 359,697
86,242
9,260
455,199
Other 12,675
—
63
12,738
Total retail 606,806
312,152
11,887
930,845
Wholesale 43,576
—
—
43,576
Transmission 14,639
—
—
14,639
Other 16,695
22,610
—
39,305
Total revenue from contracts with customers 681,716
334,762
11,887
1,028,365
Alternative revenue and other 29,672
21,374
1,123
52,169
Total revenues $ 711,388
$ 356,136
$ 13,010
$ 1,080,534

Item 2 — MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

Discussion of financial condition and liquidity for PSCo is omitted per conditions set forth in general instructions H (1) (a) and (b) of Form 10-Q for wholly owned subsidiaries. It is replaced with management’s narrative analysis of the results of operations set forth in general instructions H (2) (a) of Form 10-Q for wholly owned subsidiaries (reduced disclosure format).

~~Financial Review~~

The following discussion and analysis by management focuses on those factors that had a material effect on PSCo’s financial condition, results of operations and cash flows during the periods presented, or are expected to have a material impact in the future. It should be read in conjunction with the accompanying unaudited consolidated financial statements and related notes to the consolidated financial statements. Due to the seasonality of PSCo’s electric and natural gas sales, such interim results are not necessarily an appropriate base from which to project annual results.

~~Forward-Looking Statements~~

Except for the historical statements contained in this report, the matters discussed herein, are forward-looking statements that are subject to certain risks, uncertainties and assumptions. Such forward-looking statements including the TCJA’s impact to PSCo and its customers, rate base, valuation of deferred tax assets and liabilities, cash flow, and potential regulatory options, as well as assumptions and other statements identified in this document by the words “anticipate,” “believe,” “could,” “estimate,” “expect,” “intend,” “may,” “objective,” “outlook,” “plan,” “project,” “possible,” “potential,” “should,” “will,” “would” and similar expressions. Actual results may vary materially. Forward-looking statements speak only as of the date they are made, and we expressly disclaim any obligation to update any forward-looking information. The following factors, in addition to those discussed elsewhere in this Quarterly Report on Form 10-Q and in other securities filings (including PSCo’s Annual Report on Form 10-K for the fiscal year ended Dec. 31, 2017 and subsequent securities filings), could cause actual results to differ materially from management expectations as suggested by such forward-looking information: general economic conditions, including inflation rates, monetary fluctuations and their impact on capital expenditures and the ability of PSCo and its subsidiaries to obtain financing on favorable terms; business conditions in the energy industry; including the risk of a slow down in the U.S. economy or delay in growth, recovery, trade, fiscal, taxation and environmental policies in areas where PSCo has a financial interest; customer business conditions; actions of credit rating agencies; competitive factors including the extent and timing of the entry of additional competition in the markets served by PSCo and its subsidiaries; unusual weather; effects of geopolitical events, including war and acts of terrorism; cyber security threats and data security breaches; state, federal and foreign legislative and regulatory initiatives that affect cost and investment recovery, have an impact on rates or have an impact on asset operation or ownership or impose environmental compliance conditions; structures that affect the speed and degree to which competition enters the electric and natural gas markets; costs and other effects of legal and administrative proceedings, settlements, investigations and claims; financial or regulatory accounting policies imposed by regulatory bodies; outcomes of regulatory proceedings; availability or cost of capital; and employee work force factors.

Non-GAAP Financial Measures

The following discussion includes financial information prepared in accordance with GAAP, as well as certain non-GAAP financial measures such as electric margin, ~~and~~ natural gas ~~margin.~~margin and ongoing earnings. Generally, a non-GAAP financial measure is a ~~numerical~~ measure of a company’s financial performance, financial position or cash flows that excludes (or includes) amounts that are adjusted from ~~the most directly comparable measure~~measures calculated and presented in accordance with GAAP. PSCo’s management uses non-GAAP measures ~~internally~~ for financial planning and analysis, for reporting of results, ~~to the Board of Directors~~in determining performance-based compensation and ~~when~~ communicating its earnings outlook to analysts and investors. Non-GAAP financial measures are intended to supplement investors’ understanding of our ~~operating~~ performance and should not be considered alternatives for financial measures presented in accordance with GAAP. These measures are discussed in more detail below and may not be comparable to other companies’ similarly titled non-GAAP financial measures.

Electric and Natural Gas Margins

Electric margin is presented as electric revenues less electric fuel and purchased power ~~expenses and natural~~expenses. Natural gas margin is presented as natural gas revenues less the cost of natural gas sold and transported. Expenses incurred for electric fuel and purchased power and the cost of natural gas ~~sold and transported~~ are generally recovered through various regulatory recovery ~~mechanisms, and as~~mechanisms. As a result, changes in these expenses are generally offset in operating revenues.

Management believes electric and natural gas margins provide the most meaningful basis for evaluating our operations because they exclude the revenue impact of fluctuations in these expenses. These margins can be reconciled to operating income, a GAAP measure, by including ~~steam and~~ other operating revenues, cost of ~~sales - steam and other,~~sales-other, O&M expenses, ~~DSM~~conservation and demand side management expenses, depreciation and amortization and taxes (other than income taxes).

Results of Operations

PSCo’s net income was approximately ~~$134~~$138.8 million for the first quarter of ~~2018,~~2019, compared with approximately ~~$112~~$133.7 million for the same period of ~~2017. The increase was driven by higher~~2018. Electric and natural gas margins ~~(due to the impact of an interim rate increase, subject to refund, and~~both benefited from favorable ~~weather) and increased allowance for funds used during construction (AFUDC) primarily related to the Rush Creek wind project.~~weather. These items were partially offset by higher depreciation ~~expense.~~

expense, O&M expenses, interest charges, and decreased AFUDC. Changes in depreciation expense and AFUDC are primarily driven by the Rush Creek wind project being placed in-service in late 2018. Depreciation was also impacted by additional amortization resulting from a tax reform settlement.

Electric ~~Revenues and~~ Margin

Electric revenues and fuel and purchased power expenses are impacted by fluctuations in the price of natural gas and coal used in the generation of electricity. However, these price fluctuations have minimal impact on electric margin due to fuel recovery mechanisms that recover fuel expenses. ~~The following table details the~~In addition, electric customers receive a credit for PTCs that are generated in a particular period.

Electric revenues and margin:


	Three Months Ended March 31						Three Months Ended March 31
(Millions of Dollars)	2018			2017			2019			2018
Electric revenues	$	720		$	711		$	741.5		$	698.3
Electric fuel and purchased power	(281		)	(289		)	(304.2		)	(281.2		)
Electric margin before impact of the TCJA	$	439		$	422
Impact of the TCJA (offset as a reduction in income tax expense)	(22		)	—
Electric margin	$	417		$	422		$	437.3		$	417.1

~~The following tables summarize the components of the changes~~Changes in electric ~~revenues and electric margin for the three months ended March 31:~~

~~Electric Revenues~~margin:

(Millions of Dollars) 2018 vs. 2017
Demand side management (DSM) program revenues (offset by expenses) $ 4
Trading 4
Estimated impact of weather 2
Non-fuel riders 2
Fuel and purchased power cost recovery (6 )
Other, net 3
Total increase in electric revenues before impact of the TCJA $ 9
Impact of the TCJA (offset as a reduction in income tax expense) (22 )
Total decrease in electric revenues $ (13 )

~~Electric Margin~~

(Millions of Dollars) 2018 vs. 2017
DSM program revenues (offset by expenses) $ 4
Fuel handling and procurement 3
Conservation incentive 2
Estimated impact of weather 2
Non-fuel riders 2
Other, net 4
Total increase in electric margin before impact of the TCJA $ 17
Impact of the TCJA (offset as a reduction in income tax expense) (22 )
Total decrease in electric margin $ (5 )



(Millions of Dollars)	Three Months Ended March 31, 2019 vs. 2018
Non-fuel riders	$	20.5
Finance leases (offset in interest expense and amortization)	5.5
Estimated impact of weather	4.1
Timing of TCJA regulatory outcomes (offset in income tax)	1.3
Trading	(2.3		)
Other, net	(8.9		)
Total increase in electric margin	$	20.2

Natural Gas ~~Revenues and~~ Margin

~~Total natural~~Natural gas expense varies with changing sales and the cost of natural gas. However, fluctuations in the cost of natural gas ~~has~~have minimal impact on natural gas margin due to natural gas cost recovery mechanisms. ~~The following table details natural~~

Natural gas revenues and margin:


	Three Months Ended March 31						Three Months Ended March 31
(Millions of Dollars)	2018			2017			2019			2018
Natural gas revenues	$	372		$	356		$	469.1		$	364.0
Cost of natural gas sold and transported	(191		)	(196		)	(272.5		)	(191.3		)
Natural gas margin before impact of the TCJA	$	181		$	160
Impact of the TCJA (offset as a reduction in income tax expense)	(8		)	—
Natural gas margin	$	173		$	160		$	196.6		$	172.7

~~The following tables summarize the components of the changes~~Changes in natural gas ~~revenues and natural gas margin for the three months ended March 31:~~

~~Natural Gas Revenues~~margin:



(Millions of Dollars)	Three Months Ended March 31, 2019 vs. 2018
Retail rate increase	$	11.5
Estimated impact of weather	6.3
Retail sales growth (excluding weather impact)	2.6
Transport sales	2.6
Infrastructure and integrity riders	2.5
Other, net	(1.6		)
Total increase in natural gas margin	$	23.9

(Millions of Dollars) 2018 vs. 2017
Retail rate increase (interim, subject to refund) $ 9
Estimated impact of weather 5
Infrastructure and integrity riders 4
Purchased natural gas adjustment clause recovery (5 )
Other, net 3
Total increase in natural gas revenues before impact of the TCJA $ 16
Impact of the TCJA (offset as a reduction in income tax expense) (8 )
Total increase in natural gas revenues $ 8

~~Natural Gas Margin~~

(Millions of Dollars) 2018 vs. 2017
Retail rate increase (interim, subject to refund) $ 9
Estimated impact of weather 5
Infrastructure and integrity riders 4
Other, net 3
Total increase in natural gas margin before impact of the TCJA $ 21
Impact of the TCJA (offset as a reduction in income tax expense) (8 )
Total increase in natural gas margin $ 13

Non-Fuel Operating Expenses and Other Items

O&M Expenses— O&M expenses ~~decreased $2~~increased $16.2 million, or ~~1.1 percent,~~8.8%, for the first quarter of ~~2018. The decrease primarily reflects~~2019. Increase was driven by distribution costs and plant generation expenses. Distribution expenses were higher due to storms, labor and overtime. Plant generation amounts increased due to the in-servicing of the Rush Creek wind project and the timing of planned maintenance and ~~overhauls at generation facilities.~~overhauls.

~~DSM Program Expenses~~ — Demand side management (DSM) program expenses increased $5 million, or 16.5 percent, for the first quarter of 2018. The increase was due to higher recovery rates for electric and natural gas sales. DSM expenses are generally recovered concurrently through riders and base rates. Timing of recovery may not correspond to the period in which costs were incurred.

Depreciation and Amortization — Depreciation and amortization expense increased $7$25.3 million, or ~~5.8 percent,~~20.8%, for the first quarter of ~~2018.~~2019. The increase was primarily ~~attributable to~~driven by the Rush Creek wind project being placed in-service (rider recoverable), other capital investments ~~due~~and additional amortization of a prepaid pension asset in Colorado related to ~~planned system investments.~~tax reform settlements.

AFUDC, Equity and Debt — AFUDC ~~increased $9~~decreased $(9.0) million for the first quarter of ~~2018.~~2019. The ~~increase~~decrease was primarily ~~due to~~driven by the Rush Creek wind ~~project.~~project being placed in-service in 2018.

Interest Charges— Interest charges increased $9.6 million, or 19.2%, for the first quarter of 2019. The increase was related to higher debt levels to fund capital investments, partially offset by refinancings at lower interest rates.

Income Taxes — Income tax expense decreased ~~$26~~$19.9 million for the first quarter of ~~2018 compared with the same period in 2017.~~2019. The decrease was primarily driven by ~~a lower federal tax rate due to the TCJA and~~wind PTCs, an increase in plant-related regulatory differences related to ~~ARAM. These were partially offset by the deferral~~ARAM (net of ~~ARAM.~~deferrals) and lower pretax earnings. The ETR was ~~22.6 percent~~12.1% for the first quarter of ~~2018~~2019 compared with ~~36.9 percent~~22.6% for the same period of ~~2017.~~2018. The lower ETR in ~~2018~~2019 is primarily due to the items referenced above. See Note 6 to the consolidated financial statements.

~~Public Utility Regulation~~Pending and Recently Concluded Regulatory Proceedings

Except to the extent noted below, the circumstances set forth in Public Utility Regulation included in Item 1 of PSCo’s Annual Report on Form 10-K for the year ended Dec. 31, 2017 appropriately represent, in all material respects, the current status of public utility regulation and are incorporated herein by reference.



Mechanism	Utility Service	Amount Requested (in millions)	Filing Date	Approval	Additional Information
PSCo (CPUC)
Rate Case	Steam	$7	January 2019	Pending	Request is based on a ROE of 10.65%, an equity ratio of 56.29%, a rate base of $64.1 million and a historic test year ending Dec. 31, 2017, to be effective in October 2019. The request also includes adjustments for installation of a new water treatment system in 2018 and a new boiler at the Denver Steam plant in 2019. On April 11, 2019 CPUC Staff recommended a ROE of 9.72%, an equity ratio of 55.34%, and an increase of $5.9 million. CPUC Staff also requested PSCo file a CPCN for the investment in the water treatment system within 90 days of a final decision.
Multi-Year Rate Case	Natural Gas	$139	April 2019	Pending	PSCo filed an appeal in April 2019, seeking judicial review of the CPUC’s prior ruling regarding PSCo’s last natural gas rate case (approved in December 2018). Appeal requests review of the following: denial of a return on the prepaid pension and retiree medical assets; the use of a capital structure that is not based on the actual historical test year level; and the use of an average rate base methodology rather than a year-end rate base methodology.

~~Colorado Energy Plan (CEP)~~ — In 2016, PSCo filed its 2016 Electric Resource Plan (ERP) which included the estimated need for additional generation resources through spring of 2024. In 2017, PSCo filed an updated capacity need with the CPUC of 450 MW in 2023.

In 2017, PSCo and various other stakeholders filed a stipulation agreement (Stipulation) proposing the CEP, an alternative plan that increases the amount of new renewable resources sought under the ERP. The CEP would increase PSCo’s potential capacity need up to 1,110 MW due to the proposed retirement of two coal units. The major components include:

~~Early retirement of 660 MWs of coal-fired generation at Comanche Units 1 (2022) and 2 (2025);~~

~~Accelerated depreciation for the early retirement of the two Comanche units and establishment of a regulatory asset to collect the incremental depreciation expense and related costs;~~

~~A request for proposal (RFP) for up to 1,000 MW of wind, 700 MW of solar and 700 MW of natural gas and/or storage;~~

~~Utility ownership targets of 50 percent renewable generation resources and 75 percent of natural gas-fired, storage, or renewable with storage generation resources; and~~

~~Reduction of the renewable energy standard adjustment rider (RESA), from two percent to one percent effective beginning 2021 or 2022.~~

In March 2018, the CPUC required additional portfolio requirements beyond the terms of the Stipulation. The CPUC requested PSCo to present 750 MW and 1,100 MW portfolios, and to include a least-cost portfolio in addition to the recommended portfolio. They also requested a scenario without the RESA reduction offsetting the cost of accelerated depreciation. The order did not explicitly approve the Stipulation and deferred action on issues such as the treatment of accelerated depreciation which is being addressed in a separate proceeding.

~~PSCo is currently evaluating bids from a RFP and anticipates filing its recommended portfolios in May 2018. A CPUC decision on the recommended portfolio is anticipated in the summer of 2018.~~

~~Mountain West Transmission Group (MWTG) —~~ PSCo, along with nine other electric service providers from the Rocky Mountain region, had considered creating and operating a joint transmission tariff to increase wholesale market efficiency and improve regional transmission planning. The MWTG sought opportunities to reduce customer costs, and maximize resource and electric grid utilization. Negotiations with the ~~Southwest Power Pool (SPP)~~ ~~commenced in 2017 in order to develop potential terms for participation in the~~ ~~Regional Transmission Organization~~. As these negotiations developed, PSCo determined that the likely level of benefits was not sufficient to support continued engagement. On April 20, 2018, PSCo notified SPP, regulators and the other MWTG utility members that it was ending its participation in the regional effort.

~~Public Utility Regulatory Policies Act (PURPA) Enforcement Complaint against CPUC~~ — Sustainable Power Group, LLC (sPower) has proposed to construct 800 MW of solar generation and 700 MW of wind generation in Colorado and is seeking to require PSCo to contract for these resources under PURPA. In 2017, sPower filed a complaint for declaratory and injunctive relief in the United States District Court for the District of Colorado (District Court) requesting that the court find a December 2016 CPUC ruling that a qualifying facility must be a successful bidder in a PSCo resource acquisition bidding process violated PURPA and FERC rules. PSCo intervened in that proceeding and the CPUC filed a motion to dismiss. In June 2017, the United States Magistrate Judge issued a recommendation to the District Court that sPower’s complaint be dismissed because sPower failed to establish that it faced a substantial risk of harm. In October 2017, the District Court denied the CPUC’s motion to dismiss and instead allowed sPower to file an amended complaint. The case effectively started over, and PSCo intervened. The CPUC filed a motion to dismiss the amended complaint which is currently pending before the District Court. In February 2018, the Magistrate Judge recommended the CPUC motion to dismiss be denied. The CPUC and PSCo filed objections in March 2018. The timing of a resolution in this case is unclear.

~~OATT Reform~~Cheyenne Ridge Wind CPCN — In ~~late March~~December 2018, PSCo filed for ~~changes to its OATT with~~a CPCN for the ~~FERC. The tariff change would allow large generating interconnection agreements to be suspended only due to a force majeure event~~500 MW Cheyenne Ridge self-build wind farm and would apply only to new contracts on a prospective basis. In April 2018, certain parties filed comments opposing the PSCo tariff change. FERC action is pending. PSCo has also initiated a larger stakeholder process to achieve broader queue reform and anticipates filing additional tariff changes later in 2018.65 mile gen-tie line. On April ~~19, 2018, FERC~~24, 2019, the CPUC issued their decision which grants a final rule requiring queue reforms in addition (but generally complimentary) to reforms PSCo already contemplated; compliance tariff filings will be due in third quarter 2018. PSCo currently has more than 22,000 MW of new generator projects in its interconnection queue.CPCN and:

Includes a construction cost cap of $743 million (inclusive of AFUDC);

Establishes that PSCo will accrue AFUDC on project while under construction and will recover costs associated with Cheyenne Ridge through riders once the project is complete and before it goes into base rates; and

~~Summary of Recent Federal Regulatory Developments~~Establishes a customer protection mechanism through ongoing reporting on the project.

~~FERC~~

The FERC has jurisdiction over rates for electric transmission service in interstate commerce and electricity sold at wholesale, hydro facility licensing, natural gas transportation, asset transactions and mergers, accounting practices and certain other activities of PSCo, including enforcement of North American Electric Reliability Corporation mandatory electric reliability standards. State and local agencies have jurisdiction over many of PSCo’s activities, including regulation of retail rates and environmental matters. See additional discussion in the summary of recent federal regulatory developments and public utility regulation sections of the PSCo Annual Report on Form 10-K for the year ended Dec. 31, 2017. In addition to the matters discussed below, see Note 5 to the consolidated financial statements for a discussion of other regulatory matters.

Xcel Energy, which includes PSCo, attempts to mitigate the risk of regulatory penalties through formal training on prohibited practices and a compliance function that reviews interaction with the markets under FERC and Commodity Futures Trading Commission jurisdictions. Public campaigns are conducted to raise awareness of the public safety issues of interacting with our electric systems. While programs to comply with regulatory requirements are in place, there is no guarantee the compliance programs or other measures will be sufficient to ensure against violations.

Item 4 — CONTROLS AND PROCEDURES

Disclosure Controls and Procedures

PSCo maintains a set of disclosure controls and procedures designed to ensure that information required to be disclosed in reports that it files or submits under the Securities Exchange Act of 1934 is recorded, processed, summarized, and reported within the time periods specified in SEC rules and forms. In addition, the disclosure controls and procedures ensure that information required to be disclosed is accumulated and communicated to management, including the chief executive officer (CEO) and chief financial officer (CFO), allowing timely decisions regarding required disclosure. As of March 31, ~~2018,~~2019, based on an evaluation carried out under the supervision and with the participation of PSCo’s management, including the CEO and CFO, of the effectiveness of its disclosure controls and the procedures, the CEO and CFO have concluded that PSCo’s disclosure controls and procedures were effective.

Internal Control Over Financial Reporting

No changes in PSCo’s internal control over financial reporting occurred during the most recent fiscal quarter that materially affected, or are reasonably likely to materially affect, PSCo’s internal control over financial reporting.

Part II — OTHER INFORMATION

Item 1—~~LEGAL PROCEEDINGS~~Legal Proceedings

~~PSCo~~PSCO is involved in various litigation matters that are being defended and handled in the ordinary course of business. ~~The assessment~~Assessment of whether a loss is probable or is a reasonable possibility, and whether ~~the~~a loss or a range of loss is estimable, often involves a series of complex judgments ~~about~~regarding future events. Management maintains accruals for ~~such~~ losses that are probable of being incurred and subject to reasonable estimation. Management ~~is sometimes~~may be unable to estimate an amount or range of a reasonably possible loss in certain situations, including but not limited to when (1) ~~the~~ damages sought are indeterminate, (2) ~~the~~ proceedings are in the early stages or (3) ~~the~~ matters involve novel or unsettled legal theories. In such cases, there is considerable uncertainty regarding the timing or ultimate resolution of such matters, including a possible eventual loss.

~~Additional Information~~

See Note 69 to the consolidated financial statements ~~for further discussion of legal claims~~ and ~~environmental proceedings. See~~ Part I Item 2 ~~and Note 5 to the consolidated financial statements~~ for ~~a discussion of proceedings involving utility rates and other regulatory matters.~~further information.

Item 1A — RISK FACTORS

PSCo’s risk factors are documented in Item 1A of Part I of its Annual Report on Form 10-K for the year ended Dec. 31, ~~2017,~~2018, which is incorporated herein by reference. There have been no material changes from the risk factors previously disclosed in the Form 10-K.

Item 6— EXHIBITS

* Indicates incorporation by reference

+ Executive Compensation Arrangements and Benefit Plans Covering Executive Officers and Directors



*	~~Indicates incorporation by reference~~


Exhibit Number	Description	Report or Registration Statement	SEC File or Registration Number	Exhibit Reference
3.01*	Amended and Restated Articles of Incorporation dated July 15, 1998 ~~(Exhibit 3.01 to~~	PSCo Form 10-Q for the quarter ended Sept. 30, 2017 ~~(file no. 001-03280)).~~	001-03280	3.01
3.02*	By-Laws of PSCo as Amended and Restated on ~~Sept. 26, 2013 (Exhibit 3.02 to~~Jan. 25, 2019	PSCo Form ~~10-Q/A~~10-K for the ~~quarter~~year ended ~~Sept. 30, 2013 (file no. 001-03280)).~~Dec. 31, 2018	001-03280	3.02
4.01*	Supplemental Indenture dated as of ~~Oct.~~March 1, ~~1993,~~2019 between PSCo and ~~Morgan Guaranty Trust Company~~U.S. Bank National Association, as successor Trustee, creating $400 million principal amount of ~~New York, as trustee, providing~~4.05% First Mortgage Bonds, Series No. 33 due 2049	PSCo Form 8-K dated March 13, 2019	001-03280	4.01
10.01*+	Brett Carter’s Sign-On Bonus Terms	Xcel Energy Inc. Form 10-Q for the ~~issuance of first mortgage bonds (Exhibit 4(d)(3) to Form S-3 of Xcel Energy filed April 18, 2018 (file no. 333-224333)).~~quarter ended March 31, 2019	001-03034	10.01
31.01	Principal Executive Officer’s certifications pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
31.02	Principal Financial Officer’s certifications pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
32.01	Certification pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
~~99.01~~	~~Statement pursuant to Private Securities Litigation Reform Act of 1995.~~
101	The following materials from PSCo’s Quarterly Report on Form 10-Q for the quarter ended March 31, ~~2018~~2019 are formatted in XBRL (eXtensible Business Reporting Language): (i) the Consolidated Statements of Income, (ii) the Consolidated Statements of Comprehensive Income (iii) the Consolidated Statements of Cash Flows, (iv) the Consolidated Balance Sheets, (v) Notes to Consolidated Financial Statements, and (vi) document and entity information.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.



		Public Service Company of Colorado

April ~~27, 2018~~26, 2019	By:	/s/ JEFFREY S. SAVAGE
		Jeffrey S. Savage
		Senior Vice President, Controller
		(Principal Accounting Officer)

		/s/ ROBERT C. FRENZEL
		Robert C. Frenzel
		Executive Vice President, Chief Financial Officer and Director
		(Principal Financial Officer)

2821



Revenue Request (Millions of Dollars)	2018		2019		2020		2021		Total
Revenue request	$	74	$	75	$	60	$	36	$	245
Clean Air Clean Jobs Act (CACJA) rider conversion to base rates	90		—		—		—		90
Transmission Cost Adjustment (TCA) rider conversion to base rates	43		—		—		—		43
Total	$	207	$	75	$	60	$	36	$	378

Expected year-end rate base (billions of dollars)	$	6.8	$	7.1	$	7.3	$	7.4



	Three Months Ended March 31, 2018
	Pre-Tax Fair Value Losses Recognized During the Period in:					Pre-Tax Losses Reclassified into Income During the Period from:
(Thousands of Dollars)	Accumulated Other Comprehensive Loss		Regulatory (Assets) and Liabilities			Accumulated Other Comprehensive Loss			Regulatory Assets and (Liabilities)			Pre-Tax Gains (Losses) Recognized During the Period in Income
Derivatives designated as cash flow hedges
Interest rate	$	—	$	—		$	398	^(a)	$	—		$	—
Total	$	—	$	—		$	398		$	—		$	—
Other derivative instruments
Commodity trading	$	—	$	—		$	—		$	—		$	524		^(b)
Natural gas commodity	—		(171		)	—			2,749		^(c)	(1,581		)	^(c)
Total	$	—	$	(171	)	$	—		$	2,749		$	(1,057	)




	Three Months Ended March 31, 2017
	Pre-Tax Fair Value Losses Recognized During the Period in:					Pre-Tax Losses Reclassified into Income During the Period from:
(Thousands of Dollars)	Accumulated Other Comprehensive Loss		Regulatory (Assets) and Liabilities			Accumulated Other Comprehensive Loss			Regulatory Assets and (Liabilities)			Pre-Tax Gains (Losses) Recognized During the Period in Income
Derivatives designated as cash flow hedges
Interest rate	$	—	$	—		$	398	^(a)	$	—		$	—
Total	$	—	$	—		$	398		$	—		$	—
Other derivative instruments
Commodity trading	$	—	$	—		$	—		$	—		$	379		^(b)
Natural gas commodity	—		(5,387		)	—			282		^(c)	(2,990		)	^(c)
Total	$	—	$	(5,387	)	$	—		$	282		$	(2,611	)



(Millions of Dollars)	2018 vs. 2017
Demand side management (DSM) program revenues (offset by expenses)	$	4
Trading	4
Estimated impact of weather	2
Non-fuel riders	2
Fuel and purchased power cost recovery	(6		)
Other, net	3
Total increase in electric revenues before impact of the TCJA	$	9
Impact of the TCJA (offset as a reduction in income tax expense)	(22		)
Total decrease in electric revenues	$	(13	)



(Millions of Dollars)	2018 vs. 2017
DSM program revenues (offset by expenses)	$	4
Fuel handling and procurement	3
Conservation incentive	2
Estimated impact of weather	2
Non-fuel riders	2
Other, net	4
Total increase in electric margin before impact of the TCJA	$	17
Impact of the TCJA (offset as a reduction in income tax expense)	(22		)
Total decrease in electric margin	$	(5	)



(Millions of Dollars)	2018 vs. 2017
Retail rate increase (interim, subject to refund)	$	9
Estimated impact of weather	5
Infrastructure and integrity riders	4
Purchased natural gas adjustment clause recovery	(5		)
Other, net	3
Total increase in natural gas revenues before impact of the TCJA	$	16
Impact of the TCJA (offset as a reduction in income tax expense)	(8		)
Total increase in natural gas revenues	$	8