UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

Sx ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

For the fiscal year endedMarch 31, 20122013 or

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

For the transition period from _______ to _______

Commission file number        0-26200

BOSTON CAPITAL TAX CREDIT FUND IV L.P.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code(617)624-8900

Securities registered pursuant to Section 12(b) of the Act:

Title of each class - Name of each exchange on which registered

None

Securities registered pursuant to Section 12(g) of the Act:

Title of class

Beneficial Assignee Certificates

Indicate by check mark if the Registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.

Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.

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.

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 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).

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

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).

DOCUMENTS INCORPORATED BY REFERENCE

None.

BOSTON CAPITAL TAX CREDIT FUND IV L.P.

FORM 10-K ANNUAL REPORT FOR THE YEAR ENDED MARCH 31, 20122013

TABLE OF CONTENTS

PART I

Item 1.           Business

Organization

Boston Capital Tax Credit Fund IV L.P. (the "Fund") is a limited partnership formed under the Delaware Revised Uniform Limited Partnership Act as of October 5, 1993. Effective as of June 1, 2001 there was a restructuring, and as a result, the Fund's general partner was reorganized as follows. The general partner of the Fund continues to be Boston Capital Associates IV L.P., a Delaware limited partnership. The general partner of the Fund’s general partner is now BCA Associates Limited Partnership, a Massachusetts limited partnership, whose sole general partner is C&M Management, Inc., a Massachusetts corporation. John P. Manning is the principal executive officer of C&M Management, Inc. The limited partner of the Fund’s general partner is Capital Investment Holdings, a general partnership whose partners are various officers and employees of Boston Capital Partners, Inc., and its affiliates. The assignor limited partner is BCTC IV Assignor Corp., a Delaware corporation which is now wholly-owned by John P. Manning.

The assignor limited partner was formed for the purpose of serving in that capacity for the Fund and will not engage in any other business. Units of beneficial interest in the limited partnership interest of the assignor limited partner are assigned by the assignor limited partner by means of beneficial assignee certificates ("BACs") to investors and investors are entitled to all the rights and economic benefits of a limited partner of the Fund including rights to a percentage of the income, gains, losses, deductions, credits and distributions of the Fund.

A Registration Statement on Form S-11 and the related prospectus, (together with each subsequently filed prospectus, the "Prospectus") were filed with the Securities and Exchange Commission and became effective December 16, 1993, in connection with a public offering (together with each subsequent offering of BACs described herein, the "Offering") in one or more series of a minimum of 250,000 BACs and a maximum of 30,000,000 BACs at $10 per BAC. On April 18, 1996, a Form S-11, which registered an additional 10,000,000 BACs for sale to the public in one or more series, became effective. On April 2, 1998, a Form S-11, which registered an additional 25,000,000 BACs for sale to the public in one or more series, became effective. On August 31, 1999, a Form S-11, which registered an additional 8,000,000 BACs for sale to the public, became effective. On July 26, 2000, a Form S-11, which registered an additional 7,500,000 BACs for sale to the public, became effective. On July 23, 2001, a Form S-11, which registered an additional 7,000,000 BACs for sale to the public, became effective. On July 24, 2002, a Form S–11, which registered an additional 7,000,000 BAC’s for sale to the public, became effective. On July 1, 2003, a Form S–11, which registered an additional 7,000,000 BAC’s for sale to the public, became effective. As of March 31, 2012,2013, subscriptions had been received and accepted by the General Partner in Series 20, Series 21, Series 22, Series 23, Series 24, Series 25, Series 26, Series 27, Series 28, Series 29, Series 30, Series 31, Series 32, Series 33, Series 34, Series 35, Series 36, Series 37, Series 38, Series 39, Series 40, Series 41, Series 42, Series 43 Series 44, Series 45 and Series 46 for 83,651,080 BACs in twenty-seven series representing capital contributions of $836,177,880 in the aggregate.

Description of Business

The Fund's principal business is to invest as a limited partner in other limited partnerships (the "Operating Partnerships") each of which will own or lease and will operate an apartment complex exclusively or partially for low- and moderate-income tenants. Each Operating Partnership in which the Fund invests owns apartment complexes, which are completed, newly-constructed, under construction or rehabilitation, or to-be constructed or rehabilitated, and which are expected to receive government assistance. Each apartment complex is expected to qualify for the low-income housing tax credit under Section 42 of the Code (the "Federal Housing Tax Credit"), providing tax benefits over a period of ten to twelve years in the form of tax credits which investors may use to offset income, subject to certain strict limitations, from other sources. Some apartment complexes may also qualify for the historic rehabilitation tax credit under Section 47 of the Code (the "Rehabilitation Tax Credit"). Section 236 (f) (ii) of the National Housing Act, as amended, and Section 101 of the Housing and Urban Development Act of 1965, as amended, each provide for the making by HUD of rent supplement payments to low income tenants in properties which receive other forms of federal assistance such as tax credits. The payments for each tenant, which are made directly to the owner of their property, generally are in such amounts as to enable the tenant to pay rent equal to 30% of the adjusted family income. Some of the apartment complexes in which the Fund has invested are receiving their rent supplements from HUD. HUD has been in the process of converting rent supplement assistance to assistance paid not to the owner of the apartment complex, but directly to the individuals. At this time, the Fund is unable to predict whether Congress will continue rent supplement programs payable directly to owners of apartment complexes.

As of March 31, 20122013 the Fund had invested in 1211 Operating Partnerships on behalf of Series 20, 65 Operating Partnership on behalf of Series 21, 2010 Operating Partnerships on behalf of Series 22, 1511 Operating Partnerships on behalf of Series 23, 1813 Operating Partnerships on behalf of Series 24, 117 Operating Partnerships on behalf of Series 25, 3931 Operating Partnerships on behalf of Series 26, 1513 Operating Partnerships on behalf of Series 27, 2420 Operating Partnerships on behalf of Series 28, 21 Operating Partnerships on behalf of Series 29, 1716 Operating Partnerships on behalf of Series 30, 2625 Operating Partnerships on behalf of Series 31, 15 Operating Partnerships on behalf of Series 32, 8 Operating Partnerships on behalf of Series 33, 1413 Operating Partnerships on behalf of Series 34, 1110 Operating Partnerships on behalf of Series 35, 119 Operating Partnerships on behalf of Series 36, 7 Operating Partnerships on behalf of Series 37, 10 Operating Partnerships on behalf of Series 38, 9 Operating Partnerships on behalf of Series 39, 16 Operating Partnerships on behalf of Series 40, 20 Operating Partnerships on behalf of Series 41, 2221 Operating Partnerships on behalf of Series 42, 23 Operating Partnerships on behalf of Series 43, 10 Operating Partnerships on behalf of Series 44, 30 Operating Partnerships on behalf of Series 45 and 15 Operating partnershipsPartnerships on behalf of Series 46. A description of these Operating Partnerships is set forth in Item 2 herein.

The business objectives of the Fund are to:

Employees

The Fund does not have any employees. Services are performed by the general partner and its affiliates and agents retained by them.

Item 1A.           Risk Factors

As used in this Item 1A, references to “we, “us” and “our” mean the Fund.

An investment in our BACs and our investments in Operating Partnerships are subject to risks. These risks may impact the tax benefits of an investment in our BACs, and the amount of proceeds available for distribution to our limited partners, if any, on liquidation of our investments.

In addition to the other information set forth in this report, you should carefully consider the following factors which could materially affect our business, financial condition or results of operations. The risks described below are not the only risks we face. Additional factors not presently known to us or that we currently deem to be immaterial also may materially adversely affect our business operations.

The ability of limited partners to claim tax losses from their investment in us is limited.

The IRS may audit us or an Operating Partnership and challenge the tax treatment of tax items. The amount of Low Income Housing Tax Credits and tax losses allocable to the investors could be reduced if the IRS were successful in such a challenge. The alternative minimum tax could reduce tax benefits from an investment in our BACs. Changes in tax laws could also impact the tax benefits from an investment in our BACs and/or the value of the Operating Partnerships. Until the Operating Partnerships have completed a mandatory fifteen year Low Income Housing Tax Credit compliance period, investors are at risk for potential recapture of Low Income Housing Tax Credits that have already been claimed.

The Low Income Housing Tax Credits rules are extremely complicated and noncompliance with these rules may have adverse consequences for BAC holders.

Noncompliance with applicable tax regulations may result in the loss of future Low Income Housing Tax Credits and the fractional recapture of Low Income Housing Tax Credits already taken. In most cases the annual amount of Low Income Housing Tax Credits that an individual can use is limited to the tax liability due on the person’s last $25,000 of taxable income. The Operating Partnerships may be sold at a price which would not result in our realizing cash distributions or proceeds from the transaction. Accordingly, we may be unable to distribute any cash to our investors. Low Income Housing Tax Credits may be the only benefit from an investment in our BACs.

Poor performance of one housing complex, or the real estate market generally, could impair our ability to satisfy our investment objectives.

Each housing complex is subject to mortgage indebtedness. If an Operating Partnership failed to pay its mortgage, it could lose its housing complex in foreclosure. If foreclosure were to occur during the first 15 years of the existence of the Fund, the loss of any remaining future Low Income Housing Tax Credits, a fractional recapture of previously claimed Low Income Housing Tax Credits, and a loss of our investment in the housing complex would occur. To the extent the Operating Partnerships receive government financing or operating subsidies, they may be subject to one or more of the following risks:

- difficulties in obtaining rent increases;

- limitations on cash distributions;

- limitations on sales or refinancing of Operating Partnerships;

- limitations on transfers of interests in Operating Partnerships;

- limitations on removal of local general partners;

- limitations on subsidy programs; and

- possible changes in applicable regulations.

The value of real estate is subject to risks from fluctuating economic conditions, including employment rates, inflation, tax, environmental, land use and zoning policies, supply and demand of similar properties, and neighborhood conditions, among others.

No trading market for the BACs exists or is expected to develop.

There is currently no active trading market for the BACs. Accordingly, limited partners may be unable to sell their BACs or may have to sell BACs at a discount. Limited partners should consider their BACs to be a long-term investment.

Investors may realize taxable gain on sale or disposition of BACs.

Upon the sale or other taxable disposition of BACs, investors will realize taxable income to the extent that their allocable share of the non-recourse mortgage indebtedness on the apartment complexes, together with the money they receive from the sale of the BACs, is greater than the original cost of their BACs. This realized taxable income is reduced to the extent that investors have suspended passive losses or credits. It is possible that the sale of BACs may not generate enough cash to pay the tax obligations arising from the sale.

Investors may have tax liability in excess of cash.

Investors eventually may be allocated profits for tax purposes which exceed any cash distributed to them. For this tax liability, the investor will have to pay federal income tax without a corresponding cash distribution.

Similarly, in the event of a sale or foreclosure of an apartment complex or a sale of BACs, an investor may be allocated taxable income, resulting in tax liability, in excess of any cash distributed to him or her as a result of such event.

Investors may not receive cash if apartment complexes are sold.

There is no assurance that investors will receive any cash distributions from the sale or refinancing of an apartment complex. The price at which an apartment complex is sold may not be large enough to pay the mortgage and other expenses which must be paid at such time. Even if there are net cash proceeds from a sale, expenses such as accrued Fund management fees and unpaid loans will be deducted pursuant to Section 4.02(a) of the Fund Agreement. If any of these events happen, investors will not get all of their investment back, and the only benefit from an investment will be the tax credits received.

The sale or refinancing of the apartment complexes is dependent upon the following material factors:

Any sale may occur well after the fifteen-year federal housing tax credit compliance period.

We have insufficient sources of cash to pay our existing liabilities.

We currently do not have sufficient cash resources to satisfy our financial liabilities. Furthermore, we do not anticipate that we will have sufficient available cash to pay our future financial liabilities. Substantially all of our existing liabilities are payable to our general partner and its affiliates. Though the amounts payable to the general partner and its affiliates are contractually currently payable, we do not believe that the general partner or its affiliates will demand immediate payment of these contractual obligations in the near term; however, there can be no assurance that this will be the case. We would be materially adversely affected if the general partner or its affiliates demanded payment in the near term of our existing contractual liabilities or suspended the provision of services to us because of our inability to satisfy these obligations. All monies currently deposited, or that will be deposited in the future, into the Fund's working capital reserves are intended to be utilized to pay our existing and future liabilities.

Item 1B.           Unresolved Staff Comments

Not applicable.

Item 2.           Properties

The Fund has acquired a limited partnership interest in 445399 Operating Partnerships in 27 series, identified in the table set forth below. The apartment complexes owned by the Operating Partnerships are eligible for the Federal Housing Tax Credit. Initial occupancy of a unit in each apartment complex which initially complied with the minimum set-aside test (i.e., initial occupancy by tenants with incomes equal to no more than a designated percentage of area median income) and the rent restriction test (i.e., gross rent charged tenants does not exceed 30% of the applicable income standards) is referred to as "Qualified Occupancy." The Operating Partnerships and the respective apartment complexes are described more fully in the Prospectus. The general partner believes that there is adequate casualty insurance on the properties.

Please refer to Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations" for a more detailed discussion of operational difficulties experienced by certain of the Operating Partnerships.

Boston Capital Tax Credit Fund IV L.P. - Series 20

PROPERTY PROFILE AS OF MARCH 31, 20122013 

Boston Capital Tax Credit Fund IV L.P. - Series 21

PROPERTY PROFILE AS OF MARCH 31, 20122013

Boston Capital Tax Credit Fund IV L.P. - Series 22

PROPERTY PROFILE AS OF MARCH 31, 2012

Boston Capital Tax Credit Fund IV L.P. - Series 222013

PROPERTY PROFILE AS OF MARCH 31, 2012

Continued

Boston Capital Tax Credit Fund IV L.P. - Series 23

PROPERTY PROFILE AS OF MARCH 31, 20122013

Boston Capital Tax Credit Fund IV L.P. - Series 24

PROPERTY PROFILE AS OF MARCH 31, 2012

Boston Capital Tax Credit Fund IV L.P. - Series 242013

PROPERTY PROFILE AS OF MARCH 31, 2012

Continued

Boston Capital Tax Credit Fund IV L.P. - Series 25

PROPERTY PROFILE AS OF MARCH 31, 20122013