The Registrant hereby amends this Registration Statementregistration statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statementregistration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the Registration Statementregistration statement shall become effective on such date as the Commission, acting pursuant to said Section 8(a), may determine.

The information in this Prospectus is not complete andprospectus may be changed.change. We may not sellcomplete this exchange offer and issue these Securitiessecurities until the Registration Statementregistration statement filed with the Securities and Exchange Commission is effective. This Prospectusprospectus is not an offer to sell these Securitiessecurities and is not soliciting an offer to buy these Securitiessecurities in any Statestate where the offer or sale is not permitted.

Subject to Amendment, dated September 22, 2006

SUBJECT TO COMPLETION, DATED February 18, 2003PROSPECTUS

PROSPECTUS

Laboratory Corporation of America Holdings

OFFER TO EXCHANGE

a new series of Zero Coupon Convertible Subordinated Notes due 2021

Offer toand an Exchange Fee for all of our outstanding Liquid Yield Option^™ Notes due 2021

$350,000,000 5Subject to the Terms and Conditions described in this Prospectus

 ¹The Exchange Offer

/2% SeniorWe are offering to exchange, upon the terms and subject to the conditions set forth in this prospectus, a new series of Zero Coupon Convertible Subordinated Notes due February 1, 2013

which have been registered under the Securities Act2021 and an exchange fee of 1933

$2.50 per $1,000 aggregate principal amount at maturity for any and all of our outstanding

5 ¹/2% Senior Liquid Yield Option™ Notes due February 1, 2013

which have not been registered2021. We refer to this offer as the “exchange offer.” We refer to our existing Liquid Yield Option^™ Notes due 2021 as the “Old Notes” and to the new series of Zero Coupon Convertible Subordinated Notes due 2021 issued in exchange for the Old Notes in the exchange offer as the “New Notes.” The CUSIP numbers of the Old Notes are 50540R AB 8 and 50540R AC 6.

The New Notes

PARTICIPATING IN THE EXCHANGE OFFER AND INVESTING IN THE EXCHANGE NOTES OR ORIGINAL NOTES INVOLVE RISKS. SEE “RISK FACTORS”“RISK FACTORS” BEGINNING ON PAGE 11.13 FOR A DISCUSSION OF ISSUES THAT YOU SHOULD CONSIDER WITH RESPECT TO THE EXCHANGE OFFER.

None of our Board of Directors, Laboratory Corporation of America Holdings, the exchange agent, the information agent, the dealer manager or any other person is making any recommendation as to whether you should choose to exchange your Old Notes for New Notes plus the exchange fee.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or this transaction, passed upon the merits or fairness of this transaction, or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

The exchange offer is not being made, nor will we accept surrender or exchange from holders of original notes, in any jurisdiction in which the exchange offer or the acceptance thereof would not be in compliance with the securities or “blue sky” laws of such jurisdiction.

Each broker-dealer that receives exchange notes for its own account pursuant to this exchange offer must acknowledge that it will deliver a prospectus in connection with any resale of such exchange notes. The letter of transmittal states that by so acknowledging and by delivering a prospectus, a broker-dealer will not be deemed to admit that it is an “underwriter” within the meaning of the Securities Act of 1933. This prospectus, as it may be amended or supplemented from time to time, may be used by a broker-dealer in connection with resales of exchange notes received in exchange for original notes where such original notes were acquired by such broker-dealer as a result of market-making activities or other trading activities. We have agreed that, for a period of 180 days after the date this exchange offer expires, we will make this prospectus available to any broker-dealer for use in connection with any such resale. See “Plan of Distribution.”

LEHMAN BROTHERS

The date of this prospectus is                         , 2003.Dealer Manager

This prospectus and the letter of transmittal are first being mailed

to all holders of the original notes on                    , 2003.2006

TABLE OF CONTENTS

In this prospectus, “we,” “our,” “ours” and “us” refer to Laboratory Corporation of America Holdings and its consolidated subsidiaries unless the context otherwise requires. The terms “note” or “notes” refer to both the original notes and the exchange notes to be issued in the exchange offer. The term “holders,” when used in connection with the notes, refers to those persons who are the registered holders of the notesYou should rely only on the books of the registrar appointed under the indenture.

No dealer, salespersoninformation contained or other person is authorized to give any information or to represent anything not containedincorporated by reference in this prospectus. You shouldWe have not, rely on any unauthorized information or representations. This prospectus isand the dealer manager has not, authorized anyone to provide you with different information. We are not making an offer to exchange onlysell these securities in any jurisdiction where the notes offeredoffer or sale is not permitted. You should assume that the information contained or incorporated by this prospectus, and only under the circumstances and in those jurisdictions where it is lawful to do so. The information containedreference in this prospectus is current onlyaccurate as of itsthe date on the front cover of this prospectus only. Our business, prospects and consolidated financial condition and results of operations may have changed since that date.

This prospectus incorporates important business and financial information about us that is not included in or delivered with this document. This information is available without charge to securityholders upon written or oral request to Laboratory Corporation of America Holdings, Office of the Corporate Secretary, 358 South Main Street, Burlington, North Carolina 27215, telephone (336) 229-1127. In order for you atto receive timely delivery of the documents before the expiration date of the exchange offer, you must request the information no cost, upon your request. You can request this information by writing or telephoning us at the following address:

later than October 16, 2006.

Laboratory Corporation of America Holdings,

358 South Main Street

Burlington, North Carolina 27215

(336) 229-1127

Corporate Communications Department

Attention: Corporate Secretary our logo and other trademarks mentioned in this prospectus are the property of their respective owners.

IN ORDER TO OBTAIN TIMELY DELIVERY, YOU MUST REQUEST INFORMATION NO LATER THAN                     , 2003, WHICH IS FIVE DAYS BEFORE THE SCHEDULED EXPIRATION OF THE EXCHANGE OFFER.

i

PROSPECTUS SUMMARY

The following summary is qualified by, and should be read in its entirety byconjunction with, the more detailed information included elsewhere or incorporated by reference in this prospectus. Because this is a summary, it may not contain all the information that may be important to you. You should read the entire prospectus, includingas well as the “Risk Factors” section and the financial statements and the notes to those statements and information incorporated by reference, before making a decision whetheran investment decision. As used in this prospectus, the words “we,” “us,” “our” or “LabCorp” refer to participate inLaboratory Corporation of America Holdings and its subsidiaries, unless otherwise specified or the exchange offer.context otherwise requires.

The CompanyLaboratory Corporation of America Holdings

We are headquartered in Burlington, North Carolina, and are the second largest independent clinical laboratory company in the United States based on 2005 net revenues. Since our founding in 1971, we have grown into a national network of 36 primary laboratories and over 1,300 service sites, consisting of branches, patient service centers and STAT laboratories, which are laboratories that have the ability to perform certain routine tests quickly and report the results to the physician immediately. Through a national network of laboratories, we offer more than 4,000 differenta broad range of clinical laboratory tests whichthat are used by the medical profession in routine testing, patient diagnosis, and in the monitoring and treatment of disease. In addition, we have developed specialty and niche businesses based on certain types of specialized testing capabilities and client requirements, such as oncology testing, HIV genotyping and phenotyping, diagnostic genetics and clinical research trials. We have expanded significantly our routine and specialty testing businesses through our acquisitions of Dynacare Inc. and DIANONSystems, Inc. For the nine months ended September 30, 2002, we generated net revenues of $1,857.6 million, which include the operations of Dynacare subsequent to its acquisition on July 25, 2002.

Since our founding in 1971, we have grown into a national network of 47 primary laboratories (including our recent acquisition of DIANON) and over 1,200 service sites, consisting of branches, patient service centers and stat laboratories, which are laboratories that have the ability to perform certain routine tests quickly and report the results to the physician immediately. On July 25, 2002, we completed our acquisition of Dynacare, a provider of clinical laboratory testing services in 21 states in the United States and two provinces in Canada. The acquisition of Dynacare has enabled us to expand our national testing network and we expect to realize significant operational synergies from the acquisition. Dynacare had 2001 revenues of approximately $238.0 million and had approximately 6,300 employees at the closing date of the acquisition. On January 17, 2003 we completed our acquisition of DIANON, a leading national provider of anatomic pathology and genetic testing services with a primary focus on advanced oncology testing. DIANON had 2001 revenues of approximately $125.7 million and had approximately 1,100 employees at the closing date of the acquisition. DIANON significantly enhances our oncology testing capabilities and positions us to more effectively market and distribute the advanced testing technologies that we have developed internally or licensed from our technology partners, such as Myriad Genetics, Inc., EXACT Sciences Corporation, Celera Diagnostics and Correlogic Systems, Inc.

With over 24,000 employees, we process tests on more than 300,000 patient specimens daily and provide clinical laboratory testing services to clients in all 50 states, the District of Columbia, Puerto Rico and two provinces in Canada. Our clients include physicians, hospitals, HMOs and other managed care organizations, governmental agencies, large employers, and other independent clinical laboratories that do not have the breadth of our testing capabilities. Several hundred of our 4,000 tests are frequently used in general patient care by physicians to establish or support a diagnosis, to monitor treatment or to search for an otherwise undiagnosed condition. The most frequently-requested of these routine tests include blood chemistry analyses, urinalyses, blood cell counts, Pap smears, HIV tests, microbiology cultures and procedures and alcohol and other substance-abuse tests. We perform this core group of routine tests in each of our major laboratories using sophisticated and computerized instruments, with most results reported within 24 hours.

We have invested significantly in buildingare a leadership position in genomic and other advanced testing technologies by adding new and improved technologies for early diagnosis in three primary ways: (i) internal development efforts, (ii) acquisitions and (iii) technology licensing activities. The core of our advanced testing capabilities are our Centers of Excellence located throughout the country. The Center for Molecular Biology and

Pathology, located in Research Triangle Park, NC, is a leader in the development and application of molecular diagnostics and polymerase chain reaction, or PCR, technologies in the areas of diagnostic genetics, oncology and infectious disease. We believe these technologies may represent a significant savings to managed care organizations by increasing the detection of early stage (treatable) diseases. Our National Genetics Institute in Los Angeles, CA, develops novel, highly-sensitive PCR methods used to test for hepatitis C and other infectious agents. LabCorp, through National Genetics Institute, is the only laboratory in the United States that is FDA-approved to screen plasma for infectious diseases. Viro-Med Laboratories, Inc., our advanced virology lab based in Minneapolis, MN, offers molecular microbial testing using real-time PCR platforms. With its centralized location, proprietary molecular technologies and state-of-the-art facility, Viro-Med provides significant additional capacity to support the continued expansion of our advanced testing business. Our Center for Esoteric Testing, based in Burlington, NC, uses a wide variety of technologies to perform the largest volume of esoteric testing in our network.

Our Strategy

We believe that we have differentiated ourselves from our competitors and positioned LabCorp for continued strong growth by building a leadership position in genomic and other advanced testing technologies. We believe that our leadership position enables us to provide a broad menu of testing services for the infectious disease and cancer markets, which we believe represent two of the most significant areas of future growth in the clinical laboratory industry. Our primary strategic objective is to expand our leadership position in genomic and other advanced testing technologies and leverage our national core testing infrastructure to deliver outstanding and innovative clinical testing services to patients and physicians nationwide.

Develop and Be First to Market with New Tests.    Advances in medicine have begun fundamentally to change diagnostic testing, and new tests are allowing clinical laboratories to provide unprecedented amounts of health-related information to physicians and patients. Significant new tests introduced over the past several years include a gene-based test for human papilloma virus, Myriad Genetics’ predictive test for breast cancer and tests for HIV phenotyping and cystic fibrosis. As science continues to advance, we expect new testing technologies to emerge; therefore, we intend to continue to invest in our advanced testing capabilities so that we remain on the cutting edge of clinical laboratory testing. We have added, and expect to continue to add, new testing technologies and capabilities through a combination of internal development initiatives, technology licensing and partnership transactions and selected acquisitions. Through our national sales force, we rapidly introduce new testing technologies to our physician customers. For example, last year we entered into an exclusive sales and distribution partnership with Myriad Genetics under which we now offer certain of Myriad Genetics’ products, including a predictive test for breast cancer, to physicians throughout the United States, creating an immediate distribution pipeline into the primary care physician market for these products.

Capitalize on Unique Opportunities with Partnered Technologies.    We have announced a number of significant licensing and partnership agreements which provide us with access to exciting new testing technologies that we expect will have an increasing impact on diagnostic testing. For example, in June 2002, we announced the creation of an exclusive, long-term strategic partnership with EXACT Sciences Corporation to commercialize PreGen-Plus, EXACT Sciences’ proprietary, non-invasive technology for the early detection of colorectal cancer in the average-risk population. We currently plan to launch this gene-based test, which represents a significant new tool for the early detection of colorectal cancer, in the first half of 2003. We are collaborating with Celera Diagnostics to determine the clinical utility of laboratory tests based on novel diagnostic markers for Alzheimer’s disease, breast cancer and prostate cancer and will have exclusive access to any related markers found to have clinical utility. In addition, we recently signed a co-exclusive licensing agreement with Correlogic Systems to commercialize its ovarian cancer protein pattern blood test, which offers the prospect of accurate and early detection of ovarian cancer. With our exclusive sales and distribution partnership with Myriad Genetics, physicians now have the convenience of sending patients to one of our patient

service centers for Myriad Genetics’ predisposition testing for breast, ovarian, colon, uterine and melanoma skin cancers, as well as hypertension. Our relationship with Myriad Genetics makes us one of the few clinical laboratories in the United States to provide the entire care continuum from predisposition to surveillance testing, including screening, evaluation, diagnosis and monitoring options.

Enhance Our Oncology Testing Business by Leveraging DIANON’s Unique Capabilities.    DIANON is a national provider of oncology testing services and significantly enhances our oncology testing capabilities. DIANON is recognized by physicians, managed care companies and other customers as a leading provider of a wide range of anatomic pathology testing services, with particular strength in uropathology, dermatopathology, GI pathology and hematopathology. DIANON’s strengths in anatomic pathology complement our strengths in other areas of cancer testing, particularly cytology. We expect that DIANON’s extremely effective specialized sales force, scientific expertise, efficient operating model and proprietary CarePath clinical reporting system will allow us to enhance our cancer testing business. We intend to apply DIANON’s best practices to our existing anatomic pathology operations, through which we expect to realize significant operational efficiencies. We believe that DIANON’s sophisticated sales and marketing organization will enhance the value of our strategic cancer initiatives with Myriad Genetics, EXACT Sciences, Celera Diagnostics, Correlogic SystemsDelaware corporation, and our other technology partners as well as increase our sales potential by offering a wider range of testing services with the addition of LabCorp’s broader cancer testing menu to DIANON’s existing test menu.

Leverage National Infrastructure.    Our national presence provides us a number of significant benefits and we intend to maintain and continue to build our national presence. Our national network of 47 primary laboratories and over 1,200 service sites, including branches, patient service centers and stat laboratories, enables us to provide high-quality services to physicians, hospitals, managed care organizations and other customers across the United States and Canada. Our recent agreement with Premier, as well as our managed care contracts with United Healthcare, Aetna, MAMSI and others, demonstrate the importance of being able to deliver services on a nationwide basis. Furthermore, our scale provides us with significant cost structure advantages, particularly related to supply and other operating costs.

Expand Hospital Alliances.    Another of our primary growth strategies is to develop an increasing number of hospital and other provider alliances. These alliances can take several different forms, including laboratory technical support (management) contracts, reference agreements and cooperative testing arrangements. We have focused and will continue to focus on developing cooperative testing relationships that capitalize on hospitals’ ability to perform rapid response testing and our ability to provide high quality routine and esoteric testing.

Our principal executive office isoffices are located at 358 South Main Street, Burlington, North Carolina 27215, and our telephone number at that location is (336) 229-1127. Our website is located at www.labcorp.com. The information contained on our website is not part of this prospectus.

Recent Developments

DIANON Acquisition

On January 17, 2003, we completed the acquisition of all of the outstanding shares of DIANON for $47.50 per share in cash, or approximately $598.6 million. The transaction was funded by a combination of cash on hand, borrowings under our senior credit facilities and a new bridge loan facility. DIANON has approximately 1,100 employees who process more than 8,000 samples per day in one main testing facility and four regional labs. DIANON had 2001 revenues of approximately $125.7 million.

Senior Note Offering

On January 31, 2003, we completed a private offering of $350.0 million aggregate principal amount of our 5½% Senior Notes due February 1, 2013. We used the proceeds of this note offering and cash on hand to repay our $350.0 million bridge loan which was used to partially finance our acquisition of DIANON on January 17, 2003.

Stock Repurchase Program

On October 22, 2002, our Board of Directors authorized a stock repurchase program under which we may purchase up to an aggregate of $150.0 million of our common stock from time-to-time. It is our intention that the acquisition of common stock through the program will be funded with cash flow from operations.

Dynacare Acquisition

On July 25, 2002, we completed the acquisition of all of the outstanding stock of Dynacare in a combination cash and stock transaction with a combined value of approximately $495.3 million including transaction costs. We also converted approximately 553,958 unvested Dynacare stock options into 297,049 unvested options to acquire shares of our common stock at terms comparable to those under the predecessor Dynacare plan. In conjunction with this acquisition, we repaid Dynacare’s existing $204.4 million of senior subordinated unsecured notes, including a call premium of approximately $7.0 million. The transaction was financed by issuing approximately 4.9 million shares of our common stock, valued at approximately $245.6 million, $260.0 million in available cash, the proceeds of a $150.0 million bridge loan and borrowings of $50.0 million under our $300.0 million senior credit facilities. Dynacare had 2001 revenues of approximately $238.0 million and had approximately 6,300 employees at the closing date of the acquisition. Dynacare operates in 21 states and two provinces in Canada with 24 primary laboratories, 2 esoteric laboratories, 115 rapid response labs and 302 patient service centers.

Recent Licensing Transactions

We have entered into several strategic agreements to expand our esoteric testing capabilities. We have created an exclusive, long-term strategic partnership with EXACT Sciences to commercialize PreGen-Plus, EXACT Sciences’ proprietary, non-invasive technology for the early detection of colorectal cancer in the average-risk population. The introduction of PreGen-Plus, currently planned for the first half of 2003, will mark the broadest commercial application of discoveries made about the human genome to address a major healthcare problem such as colorectal cancer—the most deadly cancer among non-smokers in the United States. In addition, we recently have signed a co-exclusive licensing agreement with Correlogic Systems to commercialize its ovarian cancer protein pattern blood test, which offers the prospect of accurate and early detection of ovarian cancer. We have also entered into a collaboration with Celera Diagnostics to establish the clinical utility of laboratory tests based on novel diagnostic markers for Alzheimer’s disease, breast cancer and prostate cancer. This collaboration will support current and future disease association studies at Celera Diagnostics that seek to identify genetic markers associated with these important diseases, while providing us with exclusive access to the markers found to have clinical utility. Our scientists will contribute substantial scientific expertise to the validation process and our national distribution network will make new diagnostic services broadly available.

Summary of the Exchange Offer

On January 31, 2003, we completedThe following is a private offering of $350,000,000 aggregate principal amount of our 5 ¹/2% Senior Notes due February 1, 2013. Prior to the offering of those original notes, we entered into a

registration rights agreement with the initial purchasers of those original notes in which we agreed to undertake an exchange offer for those original notes. Below is abrief summary of the terms of the exchange offer. For a more complete description, see “The Exchange Offer.”

transactions, we believe that you will be able to freely transfer exchange notes acquired in the exchange offer without compliance withand will issue the provisionsNew Notes and pay the exchange fee promptly after expiration of the Securities Act that call for registrationexchange offer, upon the terms and delivery of a prospectus, unless:

Old Notes Not Tendered or Accepted for Exchange

original note offeringAny Old Notes not accepted for exchange for any reason will be returned without expense to you promptly after the expiration, termination or withdrawal of the exchange offer. If you do not exchange your Old Notes in the exchange offer, or if your Old Notes are not accepted for exchange, you will continue to hold your Old Notes, you will not receive the exchange fee, and cash on handyou will be entitled to repay our $350 million bridge loan which was usedall the rights and subject to partially finance our acquisition of DIANON Systems, Inc. on January 17, 2003.all the limitations applicable to the Old Notes.

Material Differences Between the Old Notes and the New Notes

While the terms of the New Notes are substantially similar to the terms of the Old Notes, certain material differences between the Old Notes and New Notes are described in the table below. The table below is qualified in its entirety by the information contained elsewhere in this prospectus and the documents governing the Old Notes and the New Notes, copies of which have been filed as exhibits to the registration statement of which this prospectus forms a part. For a more detailed description of the New Notes, see “Description of the New Notes.”

		Old Notes		New Notes
				•     if the conversion value exceeds the aggregate accreted principal amount of the New Notes to be converted, a number of shares of our common stock equal to the greater of (i) zero and (ii) the sum of, for each trading day of the cash settlement averaging period (as defined below), the quotient of (A) 10% of the difference between (1) the product of the conversion rate then in effect and the sale price of our common stock for such day and (2) the accreted principal amount of the New Notes on the conversion date, divided by (B) the sale price of our common stock for such day. The “accreted principal amount” with respect to $1,000 principal amount at maturity of a New Note means, at any date of determination, the sum of (1) the initial principal amount of the New Note upon issuance and (2) the accrued original issue discount that has been accreted to the principal amount of the New Note. The “conversion value” with respect to $1,000 principal amount at maturity of a New Note means, on any date of determination, the product of (1) the conversion rate then in effect and (2) the average of the sale prices of our common stock for each trading day in the cash settlement averaging period. The “cash settlement averaging period” with respect to any New Note means the ten consecutive trading days beginning on the second trading day after the conversion date (as defined under “Description of the New Notes—Conversion Rights—Payment upon Conversion”) for those New Notes. We will settle our obligation to deliver cash and shares of our common stock, if any, arising from any conversion on the third trading day following the final trading day of the relevant cash settlement averaging period.

		Old Notes		New Notes
				Unlike the Old Notes, the exact number of shares of common stock, if any, issuable upon conversion of the New Notes will not be known until the expiration of the ten-trading day cash settlement averaging period. As a result, the value of the common stock to be received on conversion may fluctuate between the time a conversion notice is delivered and the time a holder receives the common stock issued upon a conversion.
Settlement upon Conversion upon Certain Corporate Transactions		If we are party to a consolidation, merger or binding share exchange or a transfer of all or substantially all of our assets, the right to convert an Old Note into shares of our common stock will be changed into a right to convert it into the kind and amount of securities, cash or other assets of LabCorp or another person which the holder would have received if the holder had converted the holder’s Old Notes immediately prior to the transaction, assuming that such holder made no election with respect thereto and was treated alike with the plurality of non-electing holders.		If we are party to a consolidation, merger or binding share exchange or a transfer of all or substantially all of our assets, the right to convert each $1,000 principal amount at maturity of New Notes into cash and shares of our common stock, if any, will be changed into a right to convert it into the kind and amount of securities, cash or other assets (the “reference property”) of LabCorp or another person which the holder would have received if the holder had converted each $1,000 principal amount at maturity of the holder’s New Notes immediately prior to the transaction into a number of shares of our common stock equal to the then applicable conversion rate. However, at and after the effective time of the transaction, the cash portion of the payment upon conversion will continue to be payable in cash (instead of reference property), but the conversion value will be calculated based on the sale prices of the reference property during the cash settlement averaging period instead of our common stock. In determining the amount of reference property to be received by the holder of a New Note in connection with a consolidation, merger, sale or binding share exchange in which our shareholders may elect the form of consideration, the holders of the New Notes will be assumed to have elected to receive the same consideration elected by a majority of the holders of our common stock.

		Old Notes		New Notes
				Unlike the Old Notes, the exact number of shares of common stock, if any, issuable upon conversion of the New Notes will not be known until the expiration of the ten-trading day cash settlement averaging period. As a result, the value of the common stock to be received on conversion may fluctuate between the time a conversion notice is delivered and the time a holder receives the common stock issued upon a conversion.
Settlement upon Repurchase at Option of Holders		If holders of the Old Notes require us to repurchase their Old Notes at their option on September 11, 2011, we may, at our option, pay the purchase price in cash or shares of our common stock, or a combination thereof.		If holders of the New Notes require us to repurchase their New Notes at their option on September 11, 2011, we must pay the purchase price in cash only.
Accounting Treatment		We currently use the “if converted” method of accounting and have used this method since the adoption of Emerging Issues Task Force (“EITF”) 04-8. EITF 04-8 became effective for all reporting periods ending after December 15, 2004. Prior to the adoption of EITF 04-8, no shares underlying the Old Notes were included in our diluted earnings per share calculations unless the market price contingency relating to the conversion of the Old Notes was reached. However, with the adoption of EITF 04-8, the market price contingent conversion feature is effectively ignored for purposes of calculating our diluted earnings per share, and since the Old Notes provided for the delivery of shares of our common stock upon conversion in all cases, we have been accounting for the Old Notes under the “if converted” method (which provides that all shares underlying the New Notes be included when calculating our diluted earnings per share results) since the fourth quarter of 2004.		The terms of the New Notes require us to settle our conversion obligation in cash up to an amount equal to the accreted principal amount of the New Notes to be converted, with the remaining amount, if any, of our conversion obligation to be satisfied in shares of our common stock. As such, in accordance with Statement of Financial Accounting Standards (“SFAS”) No. 128, Earnings Per Share, EITF 90-19 and 04-8, we will be required to use the treasury stock equivalent method to calculate the dilutive impact on earnings per share. Under this method, our diluted shares outstanding will reflect only the shares of common stock issuable to settle the conversion obligation assuming conversion at period-end. Consequently, the New Notes will result in a lower diluted share count and higher diluted earnings per share in the future. The number of additional shares will be determined by the formula set forth in “Description of the New Notes—Conversion Rights—Payment upon Conversion.”

Summary of the Terms of the ExchangeNew Notes

The following is a summary of some of the terms of the exchange notes will be the same as the original notes, except that the exchange notes will not contain language restricting their transfer, and holdersNew Notes. For a more complete description of the exchange notes generally will not be entitled to further registration rights underterms of the registration rights agreement. The exchange notes will evidence the same debt as the outstanding original notes for which they were exchanged, and the exchange notes will replace the outstanding original notes. Both the original notes and the exchange notes are governed by the same indenture. See theNew Notes, see “Description of Exchange Notes” section of this prospectus for more detailed information about the terms and conditions of the exchange notes.New Notes.”

360-day year consisting of twelve 30-day months, at the applicable treasury rate plus 0.25%, plus accrued and unpaid interest on the principal amount of the exchange notes being redeemed to the redemption date.cash settlement averaging period.

During any period when contingent cash interest shall be payable, the contingent cash interest payable for each $1,000 principal amount at maturity of New Note in respect of any quarterly period will equal the greater of 0.0625% of the average market price of $1,000 principal amount at maturity of the New Notes for the five trading day measurement period or any regular cash dividends paid by us per share on our common stock during that quarterly period multiplied by the then applicable conversion rate, provided that if we do not pay cash dividends during a semi-annual period, we will pay contingent cash interest semi-annually at a rate of 0.125% of the average market price of $1,000 principal amount at maturity of the New Notes for the measurement period. Notwithstanding the foregoing, contingent cash interest shall be payable on the New Notes for the six-month period from September 12, 2006 to March 11, 2007, and samesolely for the purpose of determining the amount of contingent cash interest rate, maturitypayable during this six-month period, the average market price for the applicable measurement period will be determined by reference to the average market price of the Old Notes.

position and our treatment of the Old Notes, we intend to continue to treat the New Notes as debt instruments subject to the Treasury regulations that provide special rules for contingent payment debt instruments. The New Notes will continue to accrue original issue discount for U.S. federal income tax purposes. You will agree in the indenture to treat your New Notes as contingent payment debt instruments for U.S. federal income tax purposes and to be bound by our application of the Treasury regulations that govern contingent payment debt instruments, including our determination of the “comparable yield,” which is the rate at which interest income will be deemed to accrue for U.S. federal income tax purposes. Under the contingent payment debt regulations, even if we do not pay any contingent cash interest on the New Notes, holders will be required to include accrued interest income, at a rate equal to the comparable yield, in their gross income for U.S. federal income tax purposes. The comparable yield will exceed the stated yield to maturity. See “Certain U.S. Federal Income Tax Consequences.”

Risk Factors

Investing in the notes involves risks. You should refer to the section entitled “Risk Factors” for an explanation of the material risks of participating in the exchange offer and investing in the notes.

Summary Consolidated Historical and Pro Forma Financial Data

The summary consolidated historical financial data presented below (1) for each of the three years in the period ended December 31, 2001 are derived from our consolidated financial statements, which have been audited by PricewaterhouseCoopers LLP, independent accountants, and (2) as of September 30, 2001 and 2002 and for the nine month periods ended September 30, 2001 and 2002 are derived from our unaudited condensed consolidated financial statements. You should read this table along with our annual report on Form 10-K for our fiscal year ended December 31, 2001 and our quarterly report on Form 10-Q for the nine months ended September 30, 2002. Our unaudited summary consolidated financial statements include all adjustments, consisting of normal recurring adjustments, necessary for a fair presentation of our financial condition and results of operations for the relevant periods and, in the opinion of management, have been prepared on the same basis as our audited consolidated financial statements. Results of operations for the nine months ended September 30, 2002 are not necessarily indicative of results of operations for the full year. The summary unaudited pro forma consolidated financial data presented below for the year ended December 31, 2001 and at September 30, 2002 and the nine months then ended, are derived from the unaudited pro forma consolidated financial statements contained elsewhere in this document. You should read this table along with those unaudited pro forma consolidated financial statements and the accompanying notes thereto.

The following table adjusts earnings and earnings per share for the adoption of SFAS No. 142, as if it had been in effect for years presented below:

Redemption of New Notes at the Option of LabCorp

We may redeem the New Notes for cash, as a whole at any time or from time to time in part, at the redemption prices set forth under “Description of the New Notes—Redemption of New Notes at the Option of LabCorp.” We will give not less than 30 days’ or more than 60 days’ notice of redemption by mail to holders of New Notes.

RISK FACTORS

We have made in this prospectus and the documents we have incorporated by reference, and from time to time may otherwise make in our public filings, press releases and discussions with our management, forward-looking statements concerning our operations, performance and financial condition, as well as our strategic objectives. Some of these forward-looking statements can be identified by the use of forward-looking words such as “believes,” “expects,” “may,” “will,” “should,” “seeks,” “approximately,” “intends,” “plans,” “estimates” or “anticipates” or the negative of those words or other comparable terminology. Such forward-looking statements are subject to various risks and uncertainties and we claim the protection afforded by the safe harbor for forward-looking statements contained in the Private Securities Litigation Reform Act of 1995. Actual results could differ materially from those currently anticipated due to a number of factors in addition to those discussed herein and in our other public filings, press releases and discussions with our management.

You should carefully consider the risks described below with the other information contained or incorporated by reference in this prospectus before making a decision to invest in our notes. Someexchanging Old Notes for New Notes. If any of the following factors relate principally torisks actually occurs, our business, consolidated financial condition or results of operations could be materially and adversely affected. In that case the industry in which we operate. Other factors relate principally to your investment in the notes. Additional risks and uncertainties not presently known to us or that we currently deem immaterial may also adversely affect our business and operations. We are under no duty to update anytrading prices of the forward-looking statements afterNew Notes, the date of this prospectus to conform them to actual results.Old Notes and our common stock could decline substantially.

Risks Associated with the ExchangeRelating to New Notes

Our debt may impair our financialThere is no current market for the New Notes and operating flexibility.

We havewe cannot assure you that an active trading market will develop or that a significant amount of debt. As of September 30, 2002, after giving pro forma effect to the acquisition of DIANON and our borrowings associated therewith, our debt outstanding would have been $1,238.9 million. On November 29, 2002, we repaid the outstanding balance of our $150.0 million Dynacare bridge loan. On January 17, 2003, we had approximately $56.4 million of available borrowings under our senior credit facilities. On January 31, 2003, we completed the sale of our 5½% SeniorNew Notes due February 1, 2013. The net proceeds from that offering were approximately $345.1 million after deducting the discount to the initial purchasers. We used these proceeds, together with cash on hand, to repay all outstanding amounts under our $350.0 million bridge loan which we utilized to partially finance the acquisition of DIANON.

We and our subsidiaries may incur additional indebtedness in the future. If new debt is added to our current debt levels, an even greater portion of our cash flow will be needed to satisfy our debt service obligations. As a result, we would be more vulnerable to general adverse economic and industry conditions andissued in connection with the other risks associated with high levels of indebtedness. These risks could limit our ability to make payments under the notes.

Our ability to make principal and interest payments on our debt and to satisfy our other debt obligations will depend on our ability to generate cash in the future. If we do not generate sufficient cash flow to meet our debt service requirements, we may need to seek additional financing. This may make it more difficult for us to obtain financing on terms that are acceptable to us, or at all.

Secured indebtedness and borrowings by our subsidiaries will be effectively senior to the notes.exchange offer.

We conduct our operations through subsidiaries, which generate a substantial portion of our operating income and cash flow. As a result, distributions or advances from our subsidiaries are a major source of funds necessary to meet our debt service and other obligations. Contractual provisions, laws or regulations, as well as any subsidiary’s financial condition and operating requirements, may limit our ability to obtain cash required to pay our debt service obligations, including payments on the notes. The notes will be structurally subordinated to all existing and future obligations of our subsidiaries, including claims with respect to trade payables. Our

subsidiaries are limited in the amount of indebtedness they are permitted to incur pursuant to the covenant described under “Description of Exchange Notes—Certain Covenants—Limitation of Subsidiary Indebtedness and Preferred Stock.” This covenant is subject to important exceptions described under such heading. As of September 30, 2002, after giving pro forma effect to the acquisition of DIANON, our subsidiaries would have had outstanding $9.8 million of debt (including the current portion thereof).

There is currently no publicestablished trading market for the exchange notes.

New Notes. The exchange notes are a new issue of securities for which thereOld Notes may be traded on the over-the-counter market. It is currently no public market. Accordingly,expected that the New Notes will be traded in the over-the-counter market, but there can be no assurance as to the liquidity of any market that may develop for the exchange notes. We do not currently intend to apply for listingNew Notes, the ability of the exchange notesholders to sell their New Notes, or the prices at which holders of the New Notes would be able to sell their New Notes. The New Notes could trade at prices higher or lower than their initial principal amount upon issuance depending on any securities exchange.

The liquidity of, andmany factors. Accordingly, there can be no assurance that an active trading market for the exchange notes orNew Notes will develop. Furthermore, if an active trading market were to develop, the original notes, asmarket price for the case may be,New Notes may be adversely affected by general declineschanges in prevailing interest rates, our operating results, the market price of our common stock, changes in the market or by declines in theoverall market for similar securities. Such declines may adversely affect such liquiditysecurities and trading markets independent ofchanges in performance or prospects for companies in our financial performance and prospects.

The original notes are, and will continue to be, subject to restrictions on transfer, and the trading market, if any, for original notes may be adversely affected by completion of this exchange offer.

industry.

The original notes have not been registered under the Securities Act or any state securities laws and therefore may not be offered, sold or otherwise transferred except in compliance with the registration requirementsclosing of the Securities Act and any other applicable securities laws, or pursuant to an exemption from those laws or in a transaction not subject to those laws. We do not intend to register under the Securities Act the original notes that remain outstanding after completion of this exchange offer (subject to applicable limited exceptions). Original notes that remain outstanding afteris conditional upon a minimum amount of Old Notes being tendered and accepted in the completion of this exchange offer will continue to bear a legend reflecting those restrictions on transfer, and holders of those original notes will not be entitled to any rights to have those original notes registered under the Securities Act or to any similar rights under the registration rights agreement (subject to applicable limited exceptions).offer. To the extent that original notesOld Notes are not tendered and accepted for exchange in the exchange offer, the trading market, if any, for remaining original notesNew Notes could be significantly more limited than the trading market for the Old Notes. A debt security with a smaller outstanding principal amount available for trading (a smaller “float”) may command a lower price than would a comparable debt security with a larger float. Therefore, the market price for the New Notes may be affected adversely. A limited float could also make the trading price of New Notes more volatile. Issuance of New Notes will also reduce the float of the Old Notes, which may adversely affected.affect the market price of the Old Notes.

We may not have the ability to raise the funds necessary to finance the purchase of the New Notes at the option of the holders or the cash portion of the payment upon conversion of the New Notes.

On September 11, 2011, holders of the New Notes may require us to purchase their New Notes. In addition, we will be required to pay a portion of the amount due to holders of the New Notes on conversion in cash. However, it is possible that we would not have sufficient funds at that time to make the required purchase of New Notes or cash payment upon conversion of the New Notes. In addition, our ability to repurchase the New Notes or to make the cash payment upon conversion may be limited by law and the terms of the agreements relating to our indebtedness, as such indebtedness or agreements may be entered into, replaced, supplemented or amended from time to time. The use of available cash to fund the required cash payments may also impair our ability to obtain additional financing in the future. See “Description of the New Notes—Purchase of New Notes by LabCorp at the Option of the Holder” and “Description of the New Notes—Conversion Rights—Payment upon Conversion.”

The conditional conversion feature of the New Notes could result in your not being able to receive the value of the cash and shares of our common stock, if any, into which a New Note is convertible.

The New Notes are convertible into cash and, if applicable, shares of our common stock only if specified conditions are met. If the specified conditions are not met, you will not be able to convert your New Notes, and you may not be able to receive the value of the cash and, if applicable, shares of our common stock into which the New Notes would otherwise be convertible.

The net share settlement feature of the New Notes may have adverse consequences.

The New Notes will be subject to net share settlement, which means that we will satisfy our conversion obligation to holders by paying cash in settlement of the lesser of the accreted principal amount and the conversion value of the New Notes and by delivering shares of our common stock in settlement of any conversion obligation in excess of the accreted principal amount of the New Notes, as described under “Description of the New Notes—Conversion Rights—Payment upon Conversion.” Accordingly, upon conversion of a New Note, holders may not receive any shares of common stock. In addition, any settlement of a conversion of New Notes into cash and shares of our common stock will be delayed until at least the 14th trading day following our receipt of the holder’s conversion notice. Accordingly, a converting holder may receive less value than expected because the value of the shares of common stock may decline (or fail to appreciate as much as the holder may expect) between the day that the holder exercise its conversion right and the day the conversion value of the New Notes is determined.

We expect that the trading value of the New Notes will be significantly affected by the price of our common stock and other factors.

The market price of the New Notes is expected to be significantly affected by the market price of our common stock. This may result in greater volatility in the trading value of the New Notes than would be expected for nonconvertible debt securities. In addition, the price of our common stock could be affected by possible sales of our common stock by investors who view the New Notes as a more attractive means of equity participation in our company and by hedging or arbitrage trading activity that may develop involving our common stock. This hedging or arbitrage could, in turn, affect the trading value of the New Notes.

The New Notes are not protected by restrictive covenants.

The indenture governing the New Notes will not contain any financial or operating covenants or restrictions on the payment of dividends, the incurrence of indebtedness or liens or the issuance or repurchase of securities by us or any of our subsidiaries. The indenture for the New Notes also will not contain covenants or other provisions to afford protection to holders of the New Notes in the event of a change in control or other fundamental change involving us.

You should consider the U.S. federal income tax consequences of owning New Notes.

Every holder will agree with us to treat its New Notes as contingent payment debt instruments for U.S. federal income tax purposes. As a result, despite some uncertainty as to the proper application of the applicable Treasury regulations, you will be required to include in your gross income each year amounts of interest in excess of the initial yield to maturity of the New Notes. You will recognize gain or loss upon the sale, exchange, conversion or retirement of a New Note in an amount equal to the difference between the amount realized on the sale, exchange, conversion or retirement, including the fair market value of any of our common stock, if any, received, and your adjusted tax basis in the New Note. Any gain recognized by you on the sale, exchange, conversion or retirement of a New Note generally will be ordinary interest income; any loss will be ordinary loss to the extent of the interest previously included in income, and capital loss thereafter. See “Certain U.S. Federal Income Tax Consequences.”

The New Notes are subordinated in right of payment to other indebtedness.

The New Notes will be unsecured obligations subordinated in right of payment to all of our existing and future senior indebtedness. As a result, our assets will be available to pay obligations on the New Notes only after all senior indebtedness has been paid in full, and we may not have sufficient assets remaining to repay in full all of the New Notes then outstanding if we become insolvent or are forced to liquidate our assets, we default on our senior indebtedness, or the New Notes are accelerated due to any other event of default. In addition, because we are a holding company whose operations are conducted through operating subsidiaries, the New Notes will be structurally subordinated to any and all existing and future indebtedness, whether or not secured, and other liabilities and claims of holders of preferred stock of any of our subsidiaries. The New Notes will be exclusively

obligations of LabCorp. Our subsidiaries have no obligation to pay any amounts due on the New Notes. Our subsidiaries are not required to provide us with funds for our payment obligations, whether by dividends, distributions, loans or other payments. In addition, any payment of dividends, distributions, loans or advances by our subsidiaries to us could be subject to statutory or contractual restrictions. Payments to us by our subsidiaries will also be contingent upon our subsidiaries’ earnings and business considerations. The incurrence of additional indebtedness and other liabilities could materially and adversely affect our ability to pay our obligations on the New Notes. The terms of the New Notes will not limit our ability to incur senior indebtedness, and do not and will not limit our ability or the ability of our subsidiaries to incur other indebtedness or other liabilities. As of June 30, 2006, we had senior indebtedness outstanding of approximately $603.3 million. See “Description of the New Notes—Subordination.”

Risks AssociatedRelating to the Exchange Offer

The U.S. federal income tax consequences of the exchange of the Old Notes for the New Notes are not entirely clear.

The U.S. federal income tax consequences of the exchange of Old Notes for New Notes are not entirely clear. We intend to take the position that the modifications to the Old Notes resulting from the exchange offer will not constitute a significant modification of the Old Notes. By participating in the exchange offer, each holder will be deemed to have agreed, pursuant to the indenture governing the New Notes, to treat the exchange as not constituting a significant modification of the terms of the Old Notes.

If the exchange of Old Notes for New Notes does not constitute a significant modification of the terms of the Old Notes for U.S. federal income tax purposes, the New Notes will be treated as a continuation of the Old Notes with no U.S. federal income tax consequences to a holder who exchanges Old Notes for New Notes pursuant to the exchange offer, apart from the receipt of the exchange fee, which will be treated as ordinary income. Unless an exemption applies, we may withhold at a rate of 30% from the payment of the exchange fee to any Non-U.S. Holder (as defined herein) participating in the exchange offer. If, contrary to our Businessposition, the exchange of the Old Notes for the New Notes does constitute a significant modification to the terms of the Old Notes, the U.S. federal income tax consequences to you could materially differ. See “Certain U.S. Federal Income Tax Consequences.”

If you do not exchange your Old Notes, the Old Notes you retain may become less liquid as a result of the exchange offer.

If a significant number of Old Notes are exchanged in the exchange offer, the liquidity of the trading market for the Old Notes, if any, after the completion of the exchange offer may be substantially reduced. Any Old Notes exchanged will reduce the aggregate number of Old Notes outstanding. As a result, the Old Notes may trade at a discount to the price at which they would trade if the transactions contemplated by this prospectus were not consummated, subject to prevailing interest rates, the market for similar securities and other factors. We cannot assure you that an active market in the Old Notes will exist or be maintained and we cannot assure you as to the prices at which the Old Notes may be traded.

Our Board of Directors has not made a recommendation with regard to whether or not you should tender your Old Notes in the exchange offer and we have not obtained a third-party determination that the exchange offer is fair to holders of the Old Notes.

We are not making a recommendation as to whether holders of the Old Notes should exchange them. We have not retained and do not intend to retain any unaffiliated representative to act solely on behalf of the holders of the Old Notes for purposes of negotiating the terms of the exchange offer and/or preparing a report concerning the fairness of the exchange offer. The value of the New Notes received in the exchange offer may not in the future equal or exceed the value of the Old Notes tendered and we do not take a position as to whether you ought to participate in the exchange offer.

Risks Relating to Our Business

Changes in federal, state, local and third-party payorpayer regulations or policies (or in the interpretation of current regulations or policies) may adversely affect governmental and third-party reimbursement for clinical laboratory testing.

Government payors,payers, such as Medicare and Medicaid, as well as insurers, including managed care organizations, have increased their efforts to control the cost, utilization and delivery of health care services. From time to time, Congress has considered and implemented changes in the Medicare fee schedules in conjunction with certain budgetary legislation. Further reductions of reimbursement for Medicare services may be implemented from time to time. Reimbursement for the pathology services component of our business is also subject to statutory and regulatory reduction. Reductions in the reimbursement rates of other third-party payorspayers may occur as well. These measuresSuch changes in the past have resulted in reduced prices andas well as added costs and have decreased test utilization for the clinical laboratory industry by increasing complexity and adding often more complex new regulatory and administrative requirements.

In both 2001 and 2000, we derived approximately 16% of our net revenues from tests performed for beneficiaries of the Medicare and Medicaid programs. As a result of our acquisitions of Dynacare and DIANON, we expect our percentage of revenues derived from Medicare and Medicaid to increase in 2003. In addition, our private payor business depends significantly on continued participation in these programs because physicians and

hospitals often want a single laboratory to perform all of their testing services. Certain anatomic pathology services are reimbursed under the Medicare physician fee schedule rather than the Medicare laboratory fee schedule. The 2003 Medicare physician fee schedule decreased the Medicare reimbursement by 4.4% for some of the pathology services we offer. In addition, the 2003 Medicare fee schedule for clinical testing will increase only 1%. Because a significant portion of our costs are relatively fixed, Medicare payment reductions have a direct adverse effect on our net earnings and cash flows.

In 2001 and 2000, Medicare and Medicaid reimbursement programs constituted approximately $50.3 million and $35.4 million, respectively, of DIANON’s 2001 and 2000 net revenues of $125.7 million and $95.7 million. Medicare reimbursed approximately $8.3 million in 2001 and $5.2 million in 2000 of DIANON’s net revenues from genetic testing services of $19.8 million in 2001 and $13.7 million in 2002. Clinical laboratory testing services reimbursed by Medicare in 2001 and 2000 were approximately $6.8 million and $4.1 million of DIANON’s net revenues from clinical chemistry testing services of $18.7 million and $13.3 million, respectively. Medicare reimbursement for anatomic pathology services constituted approximately $34.9 million and $26.1 million of DIANON’s net revenues from anatomic pathology testing services of $87.2 and $68.7 million in 2001 and 2000, respectively.

In 2001 and 2000, Medicare and Medicaid revenues accounted for approximately $56.2 million and $45.1 million of Dynacare’s total U.S. revenues of $297.3 million and $250.7 million, respectively, as prepared in accordance with Canadian GAAP.

Further changes in federal, state, local and third-party payorpayer regulations or policies may have a material adverse impact on our business. For a more detailed discussion of reimbursement under Medicare and Medicaid, see “Business—Regulation and Reimbursement—Payment of Clinical Laboratory Services.”

We could face significant monetary damages and penalties and/or exclusion from the Medicare and Medicaid programs if we violate healthcarehealth care anti-fraud and abuse laws.

We are subject to extensive government regulation at the federal, state and local levels. Our failure to meet governmental requirements under these regulations, including those relating to billing practices and relationships with physicians and hospitals, could lead to civil and criminal penalties, exclusion from participation in Medicare and Medicaid and possible prohibitions or restrictions on the use of our laboratories. Recently, DIANON settled a U.S. Department of Justice investigation into several of DIANON’s billing practices. As part of the settlement, DIANON entered into a voluntary corporate integrity program. DIANON previously recorded a non-recurring charge of $5.5 million in the third quarter of 2002 to cover the settlement payment to the government, as well as related legal costs. In addition, as part of DIANON’s acquisition of UroCor, Inc., DIANON assumed responsibility for, and liability relating to, an investigation of UroCor by the U.S. Department of Justice, including compliance with the UroCor corporate integrity agreement. WeWhile we believe we arehave structured our operations and relationships with care in material compliance with applicable regulations; however,an effort to meet all statutory and regulatory requirements, there is a risk that government authorities might take a contrary position. Such occurrences, regardless of their outcome, could damage our reputation and adversely affect important business relationships we have with third parties.

Our business would be harmed from the loss or suspension of a license or imposition of a fine or penalties under, or future changes in, the law or regulations of the Clinical Laboratory Improvement Act of 1967, and the Clinical Laboratory Improvement Amendments of 1988 or those of Medicare, Medicaid or other federal, state or local agencies.

The clinical laboratory testing industry is subject to extensive regulation, and many of these statutes and regulations have not been interpreted by the courts. The Clinical Laboratory Improvement Amendments of 1988, (“CLIA”)which we refer to as CLIA, extend federal oversight to virtually all clinical laboratories by requiring that they be certified by the federal government or by a federally-approved accreditation agency. The sanction for failure to comply with CLIA requirements may be suspension, revocation or limitation of a laboratory’s CLIA certificate, which is

necessary to conduct business, as well as significant fines and/or criminal penalties. In addition, we are subject to regulation under state law. State laws may require that laboratories and/or laboratory personnel meet certain qualifications, specify certain quality controls or require maintenance of certain records.

We cannot assure you that applicable statutes and regulations will not be interpreted or applied by a prosecutorial, regulatory or judicial authority in a manner that would adversely affect our business. Potential sanctions for violation of these statutes and regulations include significant fines and the suspension or loss of various licenses, certificates and authorizations, which could have a material adverse effect on our business. In addition, compliance with future legislation could impose additional requirements on us which may be costly. For a more detailed discussion of the regulation of our business, see “Business—Regulation and Reimbursement.”

Failure to comply with environmental, health and safety laws and regulations, including the federal Occupational Safety and Health Administration requirementsAct and the recently passed Needlestick Safety and Prevention Act, which may result in fines and penalties and loss of licensure, wouldand have a material adverse effect upon our business.

We are subject to licensing and regulation under federal, state and local laws and regulations relating to the protection of the environment and human health and safety, including laws and regulations relating to the handling, transportation and disposal of medical specimens, infectious and hazardous waste and radioactive materials as well

as to the safety and health of laboratory employees. All of our laboratories are subject to applicable federal and state laws and regulations relating to biohazard disposal of all laboratory specimens, and we utilize outside vendors for disposal of such specimens. In addition, the federal Occupational Safety and Health Administration has established extensive requirements relating to workplace safety for health care employers, including clinical laboratories, whose workers may be exposed to blood-borne pathogens such as HIV and the hepatitis B virus. These regulations,requirements, among other things, require work practice controls, protective clothing and equipment, training, medical follow-up, vaccinations and other measures designed to minimize exposure to, and transmission of, blood-borne pathogens. In addition, the federally-enacted Needlestick Safety and Prevention Act requires, among other things, that we include in our safety programs the evaluation and use of engineering controls such as safety needles if found to be effective at reducing the risk of needlestick injuries in the workplace.

Failure to comply with these federal, state and local laws and regulations could subject us to denial of the right to conduct business, fines, criminal penalties and/or other enforcement actions which would have a material adverse effect on our business. In addition, compliance with future legislation could impose additional requirements on us which may be costly.

Failure to comply withRegulations requiring the final regulationsuse of “standard transactions” for health care services issued under HIPAA may negatively impact our profitability and cash flows.

Pursuant to the Health Insurance Portability and AccountabilityAccounting Act of 1996, could result in civil and/or criminal penalties.

Regulations have been issued underwhich we refer to as HIPAA, the administrative simplification provisionsSecretary of the Health Insurance Portability and Accountability Act of 1996 (“HIPAA”). These include the Transactions and Code Sets Rule, the Privacy Rule, and the National Standard Employer Identifier Rule, which requires the use of a unique employer identifier in connection with certain electronic transactions. These regulations apply to health plans, health care providers that conduct standard transactions electronically, and health care clearinghouses (“covered entities”). It is anticipated that an enforcement regulation and a security regulation will be issued and/or finalized in 2003.

The Transactions and Code Sets Rule standardizes the format and data content to be used in the most common electronic health care transactions, including, among others, health care claims, eligibility and health care claim status. The compliance date for this rule was October 16, 2002; however, under the Administrative Simplification Compliance Act, covered entities (except small health plans) were permitted to file an extension plan with the Department of Health and Human Services, beforeor HHS, has issued final regulations designed to improve the efficiency and effectiveness of the health care system by facilitating the electronic exchange of information in certain financial and administrative transactions while protecting the privacy and security of the information exchanged.

HHS issued guidance on July 24, 2003 stating that it will not penalize a covered entity for post-implementation date transactions that are not fully compliant with the transactions standards, if the covered entity can demonstrate its good faith efforts to comply with the standards. HHS’ stated purpose for this flexible enforcement position was to “permit health plans to mitigate unintended adverse effects on covered entities’ cash flow and business operations during the transition to the standards, as well as on the availability and quality of patient care.” However, beginning October 16, 20021, 2005, the Center for Medicare and Medicaid Services no longer processes incoming non-HIPAA-compliant electronic Medicare claims.

The HIPAA transaction standards are complex, and subject to extenddifferences in interpretation by payers. For instance, some payers may interpret the standards to require us to provide certain types of information, including demographic information not usually provided to us by physicians. As a result of inconsistent application of transaction standards by payers or our inability to obtain certain billing information not usually provided to us by physicians, we could face increased costs and complexity, a temporary disruption in receipts and ongoing reductions in reimbursements and net revenues. In addition, new requirements for additional standard transactions, such as claims attachments or use of a national provider identifier, could prove technically difficult, time-consuming or expensive to implement. We are working closely with our payers to establish acceptable protocols for claims submissions and with our trade association and an industry coalition to present issues and problems as they arise to the appropriate regulators and standards setting organizations.

Compliance with the HIPAA security regulations and privacy regulations may increase our costs.

The HIPAA privacy and security regulations, which became fully effective in April 2003 and April 2005 respectively, establish comprehensive federal standards with respect to the uses and disclosures of protected health information by health plans, healthcare providers and healthcare clearinghouses, in addition to setting standards to protect the confidentiality, integrity and availability of protected health information. The regulations establish a complex regulatory framework on a variety of subjects, including:

We have implemented policies and procedures related to compliance date to October 16, 2003.with the HIPAA privacy and security regulations, as required by law. The extension plan wasprivacy regulations establish a “floor” and do not supersede state laws that are more stringent. Therefore, we are required to describe howcomply with both federal privacy regulations and varying state privacy laws. In addition, for healthcare data transfers from other countries relating to citizens of those countries, we will come into compliancemust comply with the

Transactions laws of those other countries. The federal privacy regulations restrict our ability to use or disclose patient identifiable laboratory data, without patient authorization, for purposes other than payment, treatment or healthcare operations (as defined by HIPAA), except for disclosures for various public policy purposes and Code Sets Rule requirements byother permitted purposes outlined in the compliance date. Weprivacy regulations. The privacy and each of our operating subsidiaries have filed extension planssecurity regulations provide for significant fines and expect to meet the compliance date of October 16, 2003.

The Privacy Rule regulates theother penalties for wrongful use andor disclosure of protected health information, (“PHI”) by covered entities. Itincluding potential civil and criminal fines and penalties. Although the HIPAA statute and regulations do not expressly provide for a private right of damages, we also sets forth certain rights that an individual has with respectcould incur damages under state laws to his or her PHI maintained by a covered entity, such asprivate parties for the right to access or amend certain records containing PHI or to request restrictions on thewrongful use or disclosure of PHI. Additionally, it requires covered entities to implement certain administrative requirements, such as designating a privacy officer, drafting and implementing privacy policies and procedures and training workforce members. Health care providers governed by the Privacy Rule must come into compliance by April 14, 2003.

Our HIPAA project plans have two phases: (i) assessment of current systems, applications, processes and procedure testing and validation for HIPAA compliance and (ii) remediation of affected systems, applications, processes and procedure testing and validation for HIPAA compliance.

We have completed the assessment phase of the Transactions and Code Sets provision. Remediation is currently in progress and we expect to meet the October 16, 2003 compliance date. We have completed the assessment phase of the Privacy provision. We have made financial projections and initiated remedial measures designed to meet the April 14, 2003 compliance deadline. There are, however, many unresolved issues in both of these areas and future interpretations of HIPAA could impose significant costs on us.

In addition to the federal HIPAA regulations described above, there are a number of state laws regarding the confidentiality of medicalconfidential health information some of which apply to clinical laboratories. These laws vary widely, and new laws in this area are pending, but they most commonly restrict the use and disclosure of medicalor other private personal information. Failure to comply with the HIPAA regulations and state privacy laws could result in sanctions against a laboratory’s state licensure, as well as civil and/or criminal penalties, including significant fines and imprisonment of responsible personnel, which would have a material adverse effect on our business.

Increased competition, including price competition, could have a material adverse impact on our net revenues and profitability.

The clinical laboratory business is intensely competitive both in terms of price and service. Pricing of laboratory testing services is one of the significant factors often used by health care providers and third-party payers in selecting a laboratory. As a result of the clinical laboratory industry undergoing significant consolidation, larger clinical laboratory providers are able to increase cost efficiencies afforded by large-scale automated testing. This consolidation results in greater price competition. We may be unable to increase cost efficiencies sufficiently, if at all, and as a result, our net earnings and cash flows could be negatively impacted by such price competition.

Additional competition, including price competition, could have a material adverse impact on our net revenues and profitability.

If we failFailure to develop, or acquire, licenses for new or improved testing technologies, or if our customers useusing new technologies to perform their own tests, we may not be ablelimit our ability to successfully achieve our business strategy.

The clinical laboratory testing industry is subject to changing technology and new product introductions. Our success in maintaining a leadership position in genomic and other advanced testing technologies will depend, in part, on our ability to license new and improved technologies for early diagnosis on favorable terms. We may not be able to negotiate acceptable licensing arrangements and we cannot be certain that such arrangements will yield commercially successful diagnostic tests. If we are unable to license these testing methods at competitive rates, our research and development costs may increase as a result. In addition, if we are unable to license new or improved technologies to expand our esoteric testing businesses, our testing methods

may become outdated when compared with our competition and our testing volume and revenue may be materially and adversely affected.

In addition, advances in technology may lead to the development of more cost-effective point-of-care testing equipment that can be operated by physicians or other healthcare providers in their offices or by patients themselves without requiring the services of freestanding clinical laboratories. Development of such technology and its use by our customers would reduce the demand for our laboratory testing services and negatively impact our revenues.

Currently, most clinical laboratory testing is categorized as “high” or “moderate” complexity, and thereby is subject to extensive and costly regulation under CLIA. The cost of compliance with CLIA reduces the cost effectiveness for most physicians to operate clinical laboratories in their offices, and other laws limit the ability of physicians to have ownership in a laboratory and to refer tests to such a laboratory. However, manufacturers of laboratory equipment and test kits could seek to increase their sales by marketing point-of-care laboratory equipment to physicians and by selling test kits approved for home or physician office use to both physicians and patients. Over-the-counter diagnosticsDiagnostic tests approved for home use are automatically deemed to be “waived” tests under CLIA, which may then be performed in physician office laboratories as well as by patients in their homes with minimal regulatory oversight. TheOther tests meeting certain Food and Drug Administration, or FDA, criteria also may be classified as “waived” for CLIA purposes. The FDA has regulatory responsibility over instruments, test kits, reagents and other devices used by clinical laboratories and has taken responsibility from the Centers for Disease Control for test classification.classifying the complexity of tests for CLIA purposes. Increased approval of home“waived” test kits could lead to increased testing by physicians in their offices, which could affect our market for laboratory testing services and negatively impact our revenues.

Changes in payorpayer mix, including an increase in capitated managed-cost health care or new national or networking managed care purchasing models, could have a material adverse impact on our net revenues and profitability.

Most testing services are billed to a party other than the physician or other authorized person that ordered the test. In addition, tests performedordered by a single physician may be billed to different payorspayers depending on the medical benefits of a particular patient. Increases in the percentage of services billed to government and managed care payorspayers could have an adverse impact on our net revenues. For the nine monthsyear ended September 30, 2002,December 31, 2005, the percentage of accessions by payorpayer was:

Managed care providers typically contract with a limited number of clinical laboratories and then designate the laboratory or laboratories to be used for tests ordered by participating physicians. The majority of our managed care testing is negotiated on a fee-for-service basis at a discount from our patient prices. Such discounts have historically resulted in price erosion and have negatively impacted our operating margins. In addition, managed care organizations have used capitated payment contracts in an attempt to fix the cost of laboratory testing services for their enrollees. Under a capitated payment contract, the clinical laboratory and managed care organization agree to a per member, per month payment to cover all laboratory tests during the month, regardless of the number or cost of the tests actually performed. Such contracts shift the risk of additional testing beyond that covered by the capitated payment to the clinical laboratory. Pursuant to legislation passed in late 2003, the percentage of Medicare beneficiaries enrolled in Medicare managed care plans is expected to increase. For the nine monthsyear ended September 30, 2002,December 31, 2005, capitated contracts accounted for approximately $89.3$136.5 million, or 4.1%, of our net sales.

Recently, managed care companies have announced their intention to adopt new national or networking managed care laboratory services purchasing models. If we are unable to participate in these new models, it would have a material adverse impact on our net revenues and profitability.

In addition, Medicare and Medicaid and private insurers have increased their efforts to control the cost, utilization and delivery of health care services, including clinical laboratory services. Measures to regulate health care delivery in general, and clinical laboratories in particular, have resulted in reduced prices, added costs and decreased test utilization for the clinical laboratory industry by increasing complexity and adding new regulatory

and administrative requirements. The reduction of the 2003 Medicare physician fee schedule will significantly reduce the Medicare reimbursement for pathology services we offer.

We expect efforts to impose reduced reimbursements and more stringent cost controls by government and other payers to continue. If we cannot offset additional reductions in the payments we receive for our services by reducing costs, increasing test volume and/or introducing new procedures, it would have a material adverse impact on our net revenues and profitability.

OurA failure to obtain and retain new customers and alliance partners, or a reduction in tests ordered or specimens submitted by existing customers, could impact our ability to successfully grow our business.

To offset efforts by payorspayers to reduce the cost and utilization of clinical laboratory services, we need to obtain and retain new customers and alliance partners. In addition, a reduction in tests ordered or specimens submitted by existing customers, without offsetting growth in our customer base, could impact our ability to successfully grow our business and could have a material adverse impact on our net revenues and profitability. We compete primarily on the basis of the quality of our testing, reporting and information systems, our reputation in the medical community, the pricing of our services and our ability to employ qualified personnel. Our failure to successfully compete on any of these factors could result in the loss of customers and a reduction in our ability to expand our customer base.

In addition, we rely on developing alliances with hospitals to expand our business through traditional and non-traditional business models. Reference agreements, or the traditional business model, provide a means for hospitals to outsource patient laboratory testing services that are esoteric or complex, or that are not time critical. A non-traditional business model is where we provide technical support services in a variety of health care settings. For a more detailed discussion of our alliances, see “Business—Affiliates and Alliances.” Our ability to expand the number of alliances with hospitals and maintain current alliances, many of which are terminable on short notice, could impact our ability to successfully grow our business.

OurA failure to integrate newly acquired or contracted businesses and the costs related to such integration could have a material adverse impact on our net revenues and profitability.

We are in the process of integrating into our company the operations of Dynacare and DIANON, which we acquired in July 2002 and January 2003, respectively. The integration includes the consolidation of redundant facilities and infrastructure, elimination of redundant administrative and other duplicative functions and standardization of information systems. The successful integration of Dynacare and DIANON and any business we may acquire in the future entails numerous risks, including, among others:

We cannot assure you that current or future acquisitions or contracted businesses, if any, or any related integration efforts will be successful, or that our ability to repay the notesbusiness will not be adversely affected by any future acquisitions. Even if we are able to successfully integrate the operations of Dynacare and DIANON into us, or the operations of other companies or businesses we may acquire in the future, we may not be able to realize the benefits that we expect to result from such integration, including projected cost savings within the projected time frame or at all.

Adverse results in material litigation matters could have a material adverse effect upon our business.

Although we are not currently involved in any material legal actions, we may become subject in the ordinary course of business we may become subject to material legal action related to, among other things, intellectual property disputes, professional liability and employee-related matters, as well as inquiries from governmental agencies and Medicare or Medicaid carriers requesting comment on allegations of billing irregularities that are brought to their attention through billing audits or third parties. Such future legalLegal actions could result in substantial monetary damages as well as damage to our reputation with customers, which could have a material adverse effect upon our business.

Our abilityAn inability to attract and retain experienced and qualified personnel could adversely affect our business.

The loss of key management personnel or our inability to attract and retain experienced and qualified skilled employees at our clinical laboratories and research centers could adversely affect the business. Our success is dependent in part on the efforts of key members of our management team. Our success in maintaining our leadership position in genomic and other advanced testing technologies will depend in part on our ability to attract and retain skilled research professionals. In addition, the success of our clinical laboratories also depends on employing and retaining qualified and experienced laboratory professionals, including specialists, who perform our clinical laboratory testing services. In the future, if competition for the services of these professionals increases, we may not be able to continue to attract and retain individuals in our markets. Our revenues and earnings could be adversely affected if a significant number of professionals terminate their relationship with us or become unable or unwilling to continue their employment.

Failure to maintain our days sales outstanding levels would have an adverse effect on our business.

Billing for laboratory services is a complex process. Laboratories must bill many different payorspayers such as doctors, patients, hundreds of different insurance companies, Medicare, Medicaid and employer groups, all of whomwhich have different billing requirements. We believe that a majority of our bad debt expense, which was 9.2%5.3% of our net revenues in 2001,at December 31, 2005, is the result of non-credit related issues which slow the billing process.process and patients who are unable or unwilling to pay. If we are unable to maintain our days sales outstanding level, (“DSO”),or DSO, which as of September 30, 2002 averaged 56December 31, 2005 was approximately 54 days, through efforts to reduce the number of requisitions that are missing certain billing information, our bad debt expense and DSO could increase, which would have an adverse effect on our business.

Failure in our information technology systems could significantly increase testing turn-around time or billing processes and otherwise disrupt our operations.

Our laboratory operations depend, in part, on the continued and uninterrupted performance of our information technology systems. Despite network security measures and other precautions we have taken, our information technology systems are potentially vulnerable to physical or electronic break-ins, computer viruses and similar disruptive problems. In addition, we are in the process of integrating the information technology systems of our recently acquired subsidiaries, and we may experience system failures or interruptions as a result of this process. Sustained system failures or interruption of our systems in one or more of our laboratory operations could disrupt our ability to process laboratory requisitions, perform testing, provide test results in a timely manner and/or bill the appropriate party. Failure of our information technology systems could adversely affect our business, profitability and financial condition.

Operations may be disrupted and adversely impacted by the effects of natural disasters such as hurricanes and earthquakes, or acts of terrorism or other criminal activities.

Our operations may be adversely impacted by the effects of natural disasters such as hurricanes and earthquakes, or acts of terrorism or other criminal activities. Such events may result in a temporary decline in the number of patients who seek laboratory testing services. In addition, such events may temporarily interrupt our ability to transport specimens, our ability to utilize certain laboratories or to receive material from our suppliers.

Failure to comply with the Sarbanes-Oxley Act of 2002, including Section 404 of that Act which requires management to report on, and our independent registered public accounting firm to attest to and report on, our internal controls, could cause sanctions and investigations by regulatory authorities, such as the SEC.

If we are not able to continue to comply with the requirements of Section 404 in a timely manner, our independent auditors may not be able to certify as to the effectiveness of our internal control over financial reporting and we may be subject to sanctions or investigation by regulatory authorities, such as the SEC. As a result, there could be an adverse reaction in the financial markets due to a loss of confidence in the reliability of our financial statements. In addition, we may be required to incur costs in connection with continued testing and strengthening of our internal control system.

CONSOLIDATED FORWARD-LOOKING INFORMATION

We make in this prospectus and the documents incorporated by reference into this prospectus forward-looking statements concerning our operations, performance and financial condition, as well as our strategic objectives. Some of these forward-looking statements can be identified by the use of forward-looking words such as “believes”, “expects”, “may”, “will”, “should”, “seeks”, “approximately”, “intends”, “plans”, “estimates”, or “anticipates” or the negative of those words or other comparable terminology. Such forward-looking statements are subject to various risks and uncertainties, including, but not limited to, the risks described under the heading “Risk Factors.” Actual results could differ materially from those currently anticipated due to a number of factors in addition to those discussed elsewhere in this prospectus, in the documents incorporated by referenced into this prospectus and in our other public filings, press releases and discussions with our management, including:

1. changes in federal, state, local and third party payer regulations or policies (or in the interpretation of current regulations) affecting governmental and third-party reimbursement for clinical laboratory testing;

2. adverse results from investigations of clinical laboratories by the government, which may include significant monetary damages and/or exclusion from the Medicare and Medicaid programs;

3. loss or suspension of a license or imposition of a fine or penalties under, or future changes in, the law or regulations of the Clinical Laboratory Improvement Act of 1967, and CLIA, or those of Medicare, Medicaid, the False Claims Act or other federal, state or local agencies;

4. failure to comply with the Federal Occupational Safety and Health Administration requirements and the Needlestick Safety and Prevention Act, which could result in penalties and loss of licensure;

5. failure to comply with HIPAA, which could result in significant fines;

6. failure of third party payers to complete testing with us, or accept or remit transactions in HIPAA-required standard transaction and code set format, which could result in an interruption in our cash flow;

7. increased competition, including price competition;

8. changes in payer mix, including an increase in capitated managed-cost health care or the impact of a shift to consumer-driven health plans;

9. failure to obtain and retain new customers and alliance partners, or a reduction in tests ordered or specimens submitted by existing customers;

10. failure to retain or attract managed care business as a result of changes in business models, including new risk based or network approaches, or other changes in strategy or business models by managed care companies;

11. failure to effectively manage the integration of newly acquired businesses and the cost related to such integration;

12. adverse results in litigation matters;

13. inability to attract and retain experienced and qualified personnel;

14. failure to maintain our days sales outstanding levels;

15. decrease in credit ratings by Standard & Poor’s and/or Moody’s;

16. failure to develop or acquire licenses for new or improved technologies, or the use of new technologies by customers to perform their own tests;

17. inability to commercialize newly licensed tests or technologies or to obtain appropriate reimbursement for such tests, which could result in impairment in the value of certain capitalized licensing costs;

18. inability to obtain and maintain adequate patent and other proprietary rights for protection of our products and services and successfully enforce our proprietary rights;

19. the scope, validity and enforceability of patents and other proprietary rights held by third parties that might have an impact on our ability to develop, perform, or market our tests or operate our business;

20. failure in our information technology systems resulting in an increase in testing turnaround time or a failure of billing processes or the failure to meet future regulatory or customer information technology and connectivity requirements;

21. failure of our existing and new financial information systems resulting in failure to meet required financial reporting deadlines;

22. failure of our disaster recovery plans to provide adequate protection against the interruption of business and/or the recovery of business operations;

23. business interruption or other impact on the business due to adverse weather (including hurricanes), fires and/or other natural disasters and terrorism or other criminal acts;

24. failure by us to comply with the Sarbanes-Oxley Act of 2002, including Section 404 of that Act, which requires management to report on, and our independent registered public accounting firm to attest to and report on, our internal controls; and

25. liabilities that result from any future inability to comply with new corporate governance requirements.

Except as may be required by applicable law, we undertake no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

RATIO OF EARNINGS TO FIXED CHARGES

The following table sets forth our consolidated ratiosratio of earnings to fixed charges for each of the periods shown.indicated.

These computations include us and our consolidated subsidiaries. For purposes of calculating the ratio of earnings to fixed charges, earnings consist of“earnings” represent income from continuing operations before provision for income taxes plus fixed charges. Fixed charges include“Fixed charges” represent interest expense on debt and one-thirdplus that portion of rentalrent expense which is deemed representativethat, in our opinion, approximates the interest factor included in rent expense. As of the interest factor.date of this prospectus, we have no preferred stock outstanding.

For

PRICE RANGE OF OUR COMMON STOCK

Our common stock is listed on the New York Stock Exchange under the symbol “LH.” As of September 21, 2006, the last reported sale price of our common stock on the New York Stock Exchange was$67.00. As of September 21, 2006, there were approximately 566 stockholders of record.

The following table presents, for the periods indicated, the high and low sales prices per share of our common stock as reported on the New York Stock Exchange.

DIVIDEND POLICY

We have not historically paid dividends, and we currently do not intend to pay dividends on our common stock in the future. The payment of dividends by us is subject to the discretion of our board of directors and will depend on our financial position, capital requirements and liquidity, contractual and legal requirements, results of operations and other factors. In addition, our senior credit facilities place certain limits on the payment of dividends.

SELECTED CONSOLIDATED FINANCIAL DATA

You should read the selected consolidated financial data set forth below in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and our consolidated financial statements and related notes, incorporated by reference to our Annual Report on Form 10-K for the year ended December 31, 1997, earnings were insufficient to cover fixed charges by $161.3 million.

USE OF PROCEEDS

This exchange offer is intended to satisfy some of2005 and our obligations underQuarterly Report on Form 10-Q for the registration rights agreement. We will not receive any cash proceeds from the issuance of the exchange notes in this exchange offer. In exchange for issuing the exchange notes as described in this prospectus, we will receive an equal principal amount of original notes, which will be canceled.

period ended June 30, 2006. The net proceeds from the issuance and sale of the original notes, together with cash on hand, were used to repay all outstanding amounts under our $350 million DIANON bridge loan.

CAPITALIZATION

The following table sets forth our cash and cash equivalents, total debt and total capitalizationselected consolidated financial data as of September 30, 2002 on an actual basis and:

This table should be read in conjunction with our consolidated financial statements and the related notes appearing elsewhere in this prospectus.

DESCRIPTION OF OTHER INDEBTEDNESS

Senior Credit Facilities

In February 2002, we entered into two senior credit facilities with Credit Suisse First Boston, acting through its New York Branch, acting as Administrative Agent, and a group of financial institutions totaling $300.0 million. The senior credit facilities consisted of a 364-day revolving credit facility in the principal amount of $100.0 million and a three-year revolving credit facility in the principal amount of $200.0 million.

On January 14, 2003, we entered into a new $150.0 million 364-day revolving credit facility with Credit Suisse First Boston, acting through its Cayman Islands Branch, acting as Administrative Agent, and a group of financial institutions to replace our existing $100.0 million 364-day revolving credit facility, which has been terminated. The new 364-day revolving credit facility expires on January 13, 2004. Our $200.0 million three-year revolving credit facility remains in place and expires on February 18, 2005.

As of September 30, 2002, we had no outstanding borrowings under our senior credit facilities. In connection with the DIANON acquisition, we borrowed $248.6 million under our senior credit facilities. The senior credit facilities bear interest at LIBOR plus 100 basis points and are available for general corporate purposes, including working capital, capital expenditures, funding of share repurchases and other payments and acquisitions.

Dynacare Bridge Loan

In conjunction with the acquisition of Dynacare, we borrowed $150.0 million under our Dynacare bridge loan agreement, which had an original maturity date of July 23, 2003. As of September 30, 2002, we had an outstanding balance of $120.0 million on the Dynacare bridge loan, with an interest rate of LIBOR plus 75 basis points. On November 29, 2002, we repaid all outstanding balances under the Dynacare bridge loan and as a result, the loan has been terminated.

Liquid Yield Option Notes

During 2001, we sold $744.0 million aggregate principal amount at maturity of our Liquid Yield Option Notes (the “LYONs”) in a private placement. The LYONs are zero coupon convertible subordinated notes due 2021. We received approximately $488.6 million in net proceeds from the offering and used a portion of these proceeds to repay $412.5 million of our term loan outstanding under our then existing credit agreement. The LYONs are subordinated to our senior credit facilities and to the notes being offered hereby.

Holders of the LYONs may require us to purchase all or a portion of their notes on September 11, 2004, 2006 and 2011 at prices ranging from $712.97 to $819.54 per $1,000 principal amount due at maturity. We may choose to pay the purchase price in cash or common stock or a combination of cash and common stock. If the holders elect to require us to purchase their notes, it is our current intention to purchase the notes with cash only. Should the holders put the notes to us on any of the dates above, we believe that we will be able to obtain alternate financing to satisfy this contingent cash obligation.

UNAUDITED PRO FORMA CONSOLIDATED FINANCIAL STATEMENTS

On July 25, 2002, we completed the acquisition of all of the outstanding stock of Dynacare in a combination cash and stock transaction, with a combined value of approximately $495.3 million, including transaction costs. We also converted approximately 553,958 unvested Dynacare stock options into 297,049 unvested options to acquire shares of our common stock at terms comparable to those under the predecessor Dynacare plan. This conversion of outstanding unvested options increased the non-cash consideration of the transaction by approximately $5.0 million and resulted in the recording of initial deferred compensation of approximately $2.5 million. In conjunction with this acquisition, we repaid Dynacare’s existing $204.4 million of senior subordinated unsecured notes, including a call premium of approximately $7.0 million. The transaction was financed by issuing approximately 4.9 million shares of our common stock, valued at approximately $245.6 million, $260.0 million in available cash, a $150.0 million bridge loan and borrowings of $50.0 million under our senior credit facilities.

On January 17, 2003, we completed the acquisition of all of the outstanding stock of DIANON in a cash transaction with a total value of approximately $624.0 million, including transaction costs. The transaction was financed by using approximately $25.4 million in available cash, our $350.0 million DIANON bridge loan and borrowings under our senior credit facilities.

The following unaudited pro forma consolidated financial statements have been prepared to illustrate the effects of the following transactions:

The Dynacare acquisition and the DIANON acquisition are collectively referred to by us as the Acquisitions. The borrowings under our existing senior credit facilities and the notes offered hereby are collectively referred to by us as the Borrowings.

The unaudited pro forma consolidated balance sheet as of September 30, 2002 gives effect to the acquisition of DIANON and the related borrowings as if they had occurred on September 30, 2002. The unaudited pro forma combined statements of operations assume the Acquisitions, the repayment of Dynacare’s senior subordinated unsecured notes and the Borrowings were effected on January 1, 2001. The acquisition of DIANON was accounted for under the purchase method. As such, the cost to acquire DIANON was allocated to the respective assets and liabilities acquired based on their fair values at the closing of that acquisition. The initial allocation of the costs to acquire Dynacare is already reflected in our historical balance sheet as of September 30, 2002. Initial allocations of the costs to acquire DIANON have been made to the assets and liabilities of DIANON in the accompanying unaudited pro forma consolidated financial statements based on estimates. The final allocations may be different from the amounts reflected in the accompanying unaudited pro forma consolidated financial statements.

The estimated costs associated with severance and other integration-related activities for 2002,years ended December 31, 2003, 2004 and 2005 includingare derived from audited financial statements included in our Annual Report on Form 10-K for the eliminationyear ended December 31, 2005 and incorporated by reference in this prospectus. The selected consolidated financial data as of duplicative facilitiesDecember 31, 2001, 2002 and excess capacity, operational realignment2003 and related workforce reductions,for the years ended December 31, 2001 and 2002 are derived from our audited financial statements not included or incorporated by reference in the accompanying unaudited pro formathis prospectus. The selected consolidated financial

statements. To data as of June 30, 2006 and for the extent that these costs relate to actions that impact employeesix months ended June 30, 2005 and other related activities of Dynacare or DIANON, such costs will be accounted2006, are derived from unaudited financial statements included in our Quarterly Report on Form 10-Q for as a cost of the Acquisitions. To the extent that these costs relate to actions that impact our employee and related activities, such costs will be accounted for as a charge to earnings in the periods that the integration plans are approved and communicated. During the quarter ended SeptemberJune 30, 2002, we recorded approximately $14.6 million2006 and incorporated by reference in accrued transaction costs relating to our acquisition of Dynacare. We expect to finalizethis prospectus, and record the costs associatedhave been prepared in accordance with the acquisition of DIANONaccounting principles generally accepted in the first halfUnited States for interim financial information, and in our opinion, reflect all adjustments (consisting of 2003.

The unaudited pro forma combined statementsnormal recurring adjustments) considered necessary for a fair presentation of our results of operations also do not includeand financial position. The results of operations for the estimated annual synergies that we expect to be realized upon completion of the integration of the Acquisitions in 2005.

The pro forma adjustments, and the assumptions on which they are based, are described in the accompanying notes to the unaudited pro forma consolidated financial statements.

The unaudited pro forma consolidated financial statements are presented for illustrative purposes only to aid you in your analysis of the impact on us of the Acquisitions and the Borrowings. The unaudited pro forma consolidated financial statementssix months ended June 30, 2006 are not necessarily indicative of the combined financial position or results of operations that would have been realized hadto be expected for the company, Dynacare and DIANON been a single entity during the periods presented. In addition, the unaudited pro forma consolidated financial statements are not necessarily indicative of thefull year or any future results that we will experience after the Acquisitions. The unaudited pro forma consolidated financial statements and related notes should be read in conjunction with our historical financial statements and those of Dynacare and DIANON.

Laboratory Corporation of America Holdings and Subsidiariesperiod.

Unaudited Pro Forma Consolidated Condensed Balance Sheet

As of September 30, 2002

(Dollars in millions)

See the accompanying notes to the unaudited pro forma combined balance sheet.

Laboratory Corporation of America Holdings and Subsidiaries

Notes to Unaudited Pro Forma Consolidated Condensed Balance Sheet

As of September 30, 2002

(Dollars in millions, except where indicated and for per share data)

(4)		To eliminate historical DIANON shareholders’ equity amounts as follows:
		Common stock		$	0.1
		Additional paid-in capital			256.5
		Retained earnings			35.1
		Treasury stock			(10.1	)
		Accumulated other comprehensive income			0.8
				$	282.4

LabCorp

Unaudited Pro Forma Combined Statement of Operations

Nine Months Ended September 30, 2002

(In millions, except share and per share data)