FORM OF EXCHANGE NOTE

Exhibit 4.4

FORM OF EXCHANGE NOTE

CUSIP No. 50540R AD 4

ISIN No. US50540RAD44

$350,000,000

No. A-1

5 ¹/2% Senior Note due February 1, 2013

Laboratory Corporation of America Holdings, a Delaware corporation, promises to pay to CEDE & CO., or registered assigns, the principal sum of THREE HUNDRED FIFTY MILLION Dollars on February 1, 2013.

Interest Payment Dates: February 1 and August 1, commencing August 1, 2003.

Record Dates: January 15 and July 15.

Additional provisions of this Security are set forth on the other side of this Security.

Dated:

TRUSTEE’S CERTIFICATE OF

AUTHENTICATION

Wachovia Bank, National Association

as Trustee, certifies

that this is one of

the Securities referred

to in the Indenture.

FORM OF REVERSE SIDE OF EXCHANGE NOTE

5 ¹/2% Senior Note due February 1, 2013

1.    Interest

Laboratory Corporation of America Holdings, a Delaware corporation (such corporation, and its successors and assigns under the Indenture hereinafter referred to, being herein called the “Company”), promises to pay interest on the principal amount of this Security at the rate per annum shown above. The Company will pay interest semiannually on February 1 and August 1 of each year, commencing August 1, 2003. Interest on the Securities will accrue from the most recent date to which interest has been paid or, if no interest has been paid, from January 31, 2003. Interest will be computed on the basis of a 360-day year of twelve 30-day months. The Company will pay interest on overdue principal at the rate borne by the Securities plus 1% per annum, and it will pay interest on overdue installments of interest at the same rate to the extent lawful.

2.    Method of Payment

The Company will pay interest on the Securities (except defaulted interest) to the Persons who are registered holders of Securities at the close of business on the January 15 or July 15 next preceding the interest payment date even if Securities are canceled after the record date and on or before the interest payment date. Holders must surrender Securities to a Paying Agent to collect principal payments. The Company will pay principal and interest in money of the United States that at the time of payment is legal tender for payment of public and private debts. Payments in respect of the Securities represented by a Global Security (including principal, premium and interest) will be made by wire transfer of immediately available funds to the accounts specified by The Depository Trust Company. The Company will make all payments in respect of a certificated Security (including principal, premium and interest) by mailing a check to the registered address of each Holder thereof; provided, however, that payments on a certificated Security will be made by wire transfer to a U.S. dollar account maintained by the payee with a bank in the United States if such Holder elects payment by wire transfer by giving written notice to the Trustee or the Paying Agent to such effect designating such account no later than 30 days immediately preceding the relevant due date for payment (or such other date as the Trustee may accept in its discretion).

3.    Paying Agent and Registrar

Initially, Wachovia Bank, National Association, a national banking association (the “Trustee”), will act as Paying Agent and Registrar. The Company may appoint and change any Paying Agent, Registrar or co-registrar without notice. The Company or any of its domestically incorporated Wholly Owned Subsidiaries may act as Paying Agent, Registrar or co-registrar.

4.    Indenture

The Company issued the Securities under an Indenture dated as of January 31, 2003 (“Indenture”), between the Company and the Trustee. The terms of the Securities include those stated in the Indenture and those made part of the Indenture by reference to the Trust Indenture Act of 1939 (15 U.S.C. §§ 77aaa-77bbbb) as in effect on the date of the Indenture (the “Act”). Terms defined in the Indenture and not defined herein have the meanings ascribed thereto in the Indenture. The Securities are subject to all such terms, and Securityholders are referred to the Indenture and the Act for a statement of those terms.

The Securities are general unsecured obligations of the Company. The Company shall be entitled to issue Additional Securities pursuant to Section 2.13 of the Indenture. The Initial Securities issued on the Issue Date, any Additional Securities and all Exchange Securities or Private Exchange Securities issued in exchange therefor will be treated as a single class for all purposes under the Indenture. The Indenture contains covenants that limit the ability of the Company and its Restricted Subsidiaries to create liens on assets and engage in Sale and Leaseback Transactions. The Indenture also contains a covenant that limits the ability of the Company’s

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Subsidiaries from incurring indebtedness or issuing preferred stock. These covenants are subject to important exceptions and qualifications.

5.    Optional Redemption

The Securities are subject to redemption, in whole or in part, at the option of the Company, at any time at a redemption price equal to the greater of (1) 100% of the principal amount of the Securities being redeemed plus accrued and unpaid interest to the redemption date or (2) the Make-Whole Amount for the Securities being redeemed.

“Make Whole Amount” means the sum, as determined by a Quotation Agent, of the present values of the principal amount of the Securities to be redeemed, together with scheduled payments of interest (exclusive of interest to the redemption date) from the redemption date to the maturity date of the Securities being redeemed, in each case discounted to the redemption date on a semi-annual basis, assuming a 360-day year consisting of twelve 30-day months, at the Adjusted Treasury Rate, plus accrued and unpaid interest on the principal amount of the Securities being redeemed to the redemption date.

“Adjusted Treasury Rate” means, with respect to any redemption date, (i) the yield, under the heading which represents the average for the immediately preceding week, appearing in the most recently published statistical release designated “H.15(519)” or any successor publication which is published weekly by the Board of Governors of the Federal Reserve System and which establishes yields on actively traded United States Treasury securities adjusted to constant maturity under the caption “Treasury Constant Maturities,” for the maturity corresponding to the Comparable Treasury Issue (if no maturity is within three months before or after the remaining term of the Securities of the series being redeemed, yields for the two published maturities most closely corresponding to the Comparable Treasury Issue shall be determined and the Adjusted Treasury Rate shall be interpolated or extrapolated from such yields on a straight line basis, rounding to the nearest month) or (ii) if such release (or any successor release) is not published during the week preceding the calculation date or does not contain such yields, the rate per year equal to the semi-annual equivalent yield to maturity of the Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price for such redemption date, in each case calculated on the third Business Day preceding the redemption date, plus 0.25%.

“Comparable Treasury Issue” means the United States Treasury security selected by the Quotation Agent as having a maturity comparable to the remaining term from the redemption date to the maturity date of the Securities being redeemed that would be utilized, at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable maturity to the remaining term of the Securities.

“Comparable Treasury Price” means, with respect to any redemption date, if clause (ii) of the Adjusted Treasury Rate is applicable, the average of three, or such lesser number as is obtained by the Trustee, Reference Treasury Dealer Quotations for such redemption date.

“Quotation Agent” means the Reference Treasury Dealer selected by the Company.

“Reference Treasury Dealer” means Credit Suisse First Boston Corporation and its successors and assigns, and two other nationally recognized investment banking firms selected by the Company that are primary U.S. Government securities dealers.

“Reference Treasury Dealer Quotations” means, with respect to each Reference Treasury Dealer and any redemption date, the average, as determined by the Trustee, of the bid and asked prices for the Comparable Treasury Issue, expressed in each case as a percentage of its principal amount, quoted in writing to the Trustee by such Reference Treasury Dealer at 5:00 p.m., New York City time, on the third Business Day preceding such redemption date.

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6.    Notice of Redemption

Notice of redemption will be mailed at least 30 days but not more than 60 days before the redemption date to each Holder of Securities to be redeemed at his registered address. Securities in denominations larger than $1,000 principal amount may be redeemed in part but only in whole multiples of $1,000. If money sufficient to pay the redemption price of and accrued interest on all Securities (or portions thereof) to be redeemed on the redemption date is deposited with the Paying Agent on or before the redemption date and certain other conditions are satisfied, on and after such date interest ceases to accrue on such Securities (or such portions thereof) called for redemption.

7.    Denominations; Transfer; Exchange

The Securities are in registered form without coupons in denominations of $1,000 principal amount and whole multiples of $1,000. A Holder may transfer or exchange Securities in accordance with the Indenture. The Registrar may require a Holder, among other things, to furnish appropriate endorsements or transfer documents and to pay any taxes and fees required by law or permitted by the Indenture. The Registrar need not register the transfer of or exchange any Securities selected for redemption (except, in the case of a Security to be redeemed in part, the portion of the Security not to be redeemed) or any Securities for a period of 15 days before a selection of Securities to be redeemed or 15 days before an interest payment date.

8.    Persons Deemed Owners

The registered Holder of this Security may be treated as the owner of it for all purposes.

9.    Unclaimed Money

If money for the payment of principal or interest remains unclaimed for two years, the Trustee or Paying Agent shall pay the money back to the Company at its request unless an abandoned property law designates another Person. After any such payment, Holders entitled to the money must look only to the Company and not to the Trustee for payment.

10.    Discharge and Defeasance

Subject to certain conditions, the Company at any time shall be entitled to terminate some or all of its obligations under the Securities and the Indenture if the Company deposits with the Trustee money or U.S. Government Obligations for the payment of principal and interest on the Securities to redemption or maturity, as the case may be.

11.    Amendment, Waiver

Subject to certain exceptions set forth in the Indenture, (i) the Indenture and the Securities may be amended with the written consent of the Holders of at least a majority in principal amount outstanding of the Securities and (ii) any default or noncompliance with any provision may be waived with the written consent of the Holders of a majority in principal amount outstanding of the Securities. Subject to certain exceptions set forth in the Indenture, without the consent of any Securityholder, the Company and the Trustee shall be entitled to amend the Indenture or the Securities to cure any ambiguity, omission, defect or inconsistency, or to comply with Article 5 of the Indenture, or to provide for uncertificated Securities in addition to or in place of certificated Securities, or to add guarantees with respect to the Securities or to secure the Securities, or to add additional covenants or surrender rights and powers conferred on the Company or to comply with any request of the SEC in connection with qualifying the Indenture under the Act or to make any change that does not adversely affect the rights of any Securityholder.

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12.    Defaults and Remedies

Under the Indenture, Events of Default include (i) default for 30 days in payment of interest on the Securities; (ii) default in payment of principal on the Securities, upon redemption pursuant to paragraph 5 of the Securities, upon acceleration or otherwise; (iii) failure by the Company to comply with other agreements in the Indenture or the Securities, in certain cases subject to notice and lapse of time; (iv) certain accelerations of other Indebtedness of the Company if the amount accelerated (or so unpaid) is at least $50.0 million; (v) failure by the Company or any Subsidiary to pay at maturity at least $50.0 million of other Indebtedness; and (vi) certain events of bankruptcy or insolvency with respect to the Company and its Subsidiaries.

Securityholders may not enforce the Indenture or the Securities except as provided in the Indenture. The Trustee may refuse to enforce the Indenture or the Securities unless it receives indemnity or security satisfactory to it. Subject to certain limitations, Holders of a majority in principal amount of the Securities may direct the Trustee in its exercise of any trust or power. The Trustee may withhold from Securityholders notice of any continuing Default (except a Default in payment of principal or interest) if it determines that withholding notice is in the interest of the Holders.

13.    Trustee Dealings with the Company

Subject to certain limitations imposed by the Act, the Trustee under the Indenture, in its individual or any other capacity, may become the owner or pledgee of Securities and may otherwise deal with and collect obligations owed to it by the Company or its Affiliates and may otherwise deal with the Company or its Affiliates with the same rights it would have if it were not Trustee.

14.    No Recourse Against Others

A director, officer, employee or stockholder, as such, of the Company or the Trustee shall not have any liability for any obligations of the Company under the Securities or the Indenture or for any claim based on, in respect of or by reason of such obligations or their creation. By accepting a Security, each Securityholder waives and releases all such liability. The waiver and release are part of the consideration for the issue of the Securities.

15.    Authentication

This Security shall not be valid until an authorized signatory of the Trustee (or an Authenticating Agent) manually signs the certificate of authentication on the other side of this Security.

16.    Abbreviations

Customary abbreviations may be used in the name of a Securityholder or an assignee, such as TEN COM (=tenants in common), TEN ENT (=tenants by the entireties), JT TEN (=joint tenants with rights of survivorship and not as tenants in common), CUST (=custodian), and U/G/M/A (=Uniform Gifts to Minors Act).

17.    CUSIP Numbers

Pursuant to a recommendation promulgated by the Committee on Uniform Security Identification Procedures, the Company has caused CUSIP numbers to be printed on the Securities and has directed the Trustee to use CUSIP numbers in notices of redemption as a convenience to Securityholders. No representation is made as to the accuracy of such numbers either as printed on the Securities or as contained in any notice of redemption and reliance may be placed only on the other identification numbers placed thereon.

18.    Holders’ Compliance with Registration Rights Agreement

Each Holder of a Security, by acceptance hereof, acknowledges and agrees to the provisions of the Registration Rights Agreement, including the obligations of the Holders with respect to a registration and the indemnification of the Company to the extent provided therein.

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19.    Governing Law

THIS SECURITY SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK BUT WITHOUT GIVING EFFECT TO APPLICABLE PRINCIPLES OF CONFLICTS OF LAW TO THE EXTENT THAT THE APPLICATION OF THE LAWS OF ANOTHER JURISDICTION WOULD BE REQUIRED THEREBY.

The Company will furnish to any Securityholder upon written request and without charge to the Security holder a copy of the Indenture which has in it the text of this Security in larger type. Requests may be made to:

Laboratory Corporation of America Holdings

358 South Main Street

Burlington, NC 27215

Attention: Chief Legal Officer

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ASSIGNMENT FORM

To assign this Security, fill in the form below:

I or we assign and transfer this Security to

(Print or type assignee’s name, address and zip code)

(Insert assignee’s soc. sec. or tax I.D. No.)

and irrevocably appoint                                         agent to transfer this Security on the books of the Company. The agent may substitute another to act for him.

Date:                                                                                          Your Signature:                                                                                         

Sign exactly as your name appears on the other side of this Security.

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[TO BE ATTACHED TO GLOBAL SECURITIES]

SCHEDULE OF INCREASES OR DECREASES IN GLOBAL SECURITY

The following increases or decreases in this Global Security have been made:

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