RECEIVABLES SALE AGREEMENT

Exhibit 10.4

RECEIVABLES SALE AGREEMENT

between

C AREMARK I NC . AND A DVANCE PCS H EALTH , L.P.,

as Originators,

and

C AREMARK R ECEIVABLES LLC,

as Buyer,

DATED AS OF M ARCH 24, 2004

TABLE OF CONTENTS

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RECEIVABLES SALE AGREEMENT

THIS RECEIVABLES SALE AGREEMENT , dated as of March 24, 2004 (as amended, supplemented or otherwise modified and in effect from time to time, this “Agreement” ), is entered into between CAREMARK INC. , a California corporation ( “Caremark” ), and ADVANCEPCS HEALTH, L.P., a Delaware limited partnership ( “AdvancePCS” ), as sellers (in such capacity, the “Originators” and each, an “Originator” ) and CAREMARK RECEIVABLES LLC , a Delaware limited liability company, as buyer (in such capacity, the “Buyer” ).

W I T N E S S E T H :

WHEREAS , the Buyer desires to purchase from time to time certain accounts receivable from each of the Originators existing on their respective Effective Dates (as defined in Section 7.2 hereof) and thereafter until the Purchase Termination Date (as defined in Section 8.1 hereof);

WHEREAS , each of the Originators desires to sell and assign from time to time after its respective Effective Date all of such Originator’s right, title and interest in, to and under certain accounts receivable to the Buyer upon the terms and conditions hereinafter set forth;

NOW, THEREFORE , for good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, it is hereby agreed by and between the Buyer and the Originators as follows:

ARTICLE I

DEFINITIONS

Section 1.1 Definitions .

All capitalized terms used herein shall have the meanings specified herein or, if not so specified, the meanings specified in, or incorporated by reference into, Schedule A to the Receivables Purchase Agreement, dated as of March 24, 2004 (as amended, supplemented or otherwise modified and in effect from time to time, the “Receivables Purchase Agreement” ), by and among Caremark Receivables LLC, as the seller thereunder, Caremark, as a Servicer and AdvancePCS, as a Servicer thereunder, Caremark Rx, Inc. and Caremark International, Inc., each as a Performance Guarantor various Co-Agents and Purchasers, and Wachovia Bank, National Association, as Administrative Agent thereunder.

Section 1.2 Other Terms .

All accounting terms not specifically defined herein shall be construed in accordance with generally accepted accounting principles. All terms used in Article 9 of the Uniform Commercial Code as from time to time in effect in any applicable state (the “Relevant UCC” ), and not specifically defined herein, are used herein as defined in Article 9 of the Relevant UCC.

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Section 1.3 Computation of Time Periods .

Unless otherwise stated in this Agreement, in the computation of a period of time from a specified date to a later specified date, the word “ from ” means “ from and including ” and the words “ to ” and “ until ” each means “ to but excluding. ”

ARTICLE II

PURCHASE, CONVEYANCE AND SERVICING OF RECEIVABLES

Section 2.1 Sales .

(a) Upon the terms and subject to the conditions set forth herein, and without recourse to any Originator (except to the extent specifically provided herein), each Originator hereby sells, assigns, transfers and conveys to the Buyer, and the Buyer hereby purchases from such Originator, all of such Originator’s right, title and interest, whether now owned or hereafter acquired and wherever located, in, to and under the Receivables outstanding on such Originator’s Effective Date and thereafter owned by such Originator through the Purchase Termination Date, together with all Related Security and Collections with respect thereto and all Proceeds of the foregoing. Any sale, assignment, transfer and conveyance hereunder does not constitute an assumption by the Buyer of any obligations of any Originator or any other Person to Obligors or to any other Person in connection with the Receivables or under any Related Security or any other agreement or instrument relating to the Receivables.

(b) In connection with the sales provided for herein, each Originator agrees to record and file on or prior to its respective Effective Date, at its own expense, a financing statement or statements with respect to the Receivables and the other property described in Section 2.1(a) sold by such Originator hereunder meeting the requirements of applicable state law in such manner and in such jurisdictions as are necessary to perfect and protect the interests of the Buyer created hereby under the Relevant UCC against all creditors of, and purchasers from, such Originator, and to deliver either the originals of such financing statements or file-stamped copies of such financing statements or other evidence of such filings to the Buyer on or prior to such Originator’s Effective Date.

(c) Each Originator agrees that from time to time, at its expense, it will promptly execute (if required) and deliver all instruments and documents and take all actions as may be necessary or as the Buyer may reasonably request in order to perfect or protect the interest of the Buyer in the Receivables purchased from such Originator hereunder, together with all Related Security and Collections with respect thereto and all Proceeds of the foregoing, or to enable the Buyer to exercise or enforce any of its rights hereunder. Without limiting the foregoing, each Originator will, in order to accurately reflect the purchase and sale transactions contemplated by this Agreement, file or authorize the filing of such financing or continuation statements or amendments thereto or assignments thereof (as permitted pursuant hereto) as may be requested by the Buyer and will mark its master data processing records (or related subledger) and other documents with a legend describing the purchase by the Buyer of its Receivables and the lien of

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the Administrative Agent pursuant to the Receivables Purchase Agreement and stating “ These accounts receivable have been sold to Caremark Receivables LLC. Subsequent to such sale, a security interest in the Receivables, together with all Related Security and Collections with respect thereto and all Proceeds of the foregoing, has been granted to Wachovia Bank, National Association, as Administrative Agent, pursuant to a Receivables Purchase Agreement dated as of March 24, 2004 ” . Each Originator shall, upon request of the Buyer, obtain such search reports as the Buyer shall request. To the fullest extent permitted by applicable law, the Buyer is authorized and shall be permitted to file continuation statements and amendments thereto and assignments thereof without any Originator’s signature. Carbon, photographic or other reproduction of this Agreement or any financing statement shall be sufficient as a financing statement.

(d) It is the express intent of each Originator and the Buyer that each conveyance by such Originator to the Buyer pursuant to this Agreement of the Receivables, including without limitation, all Receivables, if any, constituting general intangibles as defined in the Relevant UCC, be construed as a valid and perfected sale and absolute assignment of such Receivables by such Originator to the Buyer (rather than the grant of a security interest to secure a debt or other obligation of such Originator) and that the right, title and interest in and to such Receivables conveyed to the Buyer be prior to the rights of and enforceable against all other Persons at any time, including without limitation lien creditors, secured lenders, purchasers and any Person claiming through such Originator. However, if, contrary to the mutual intent of the parties, any conveyance of Receivables, including without limitation any Receivables constituting general intangibles, is not construed to be both a valid and perfected sale and absolute assignment of such Receivables and a conveyance of such Receivables that is prior to the rights of and enforceable against all other Persons at any time, including without limitation lien creditors, secured lenders, purchasers and any Person claiming through such Originator, then, it is the intent of such Originator and the Buyer that (i) this Agreement also shall be deemed to be, and hereby is, a security agreement within the meaning of the Relevant UCC; and (ii) such Originator shall be deemed to have granted to the Buyer as of the date of this Agreement, and such Originator hereby grants to the Buyer a security interest in, to and under all of such Originator’s rights, titles and interests in, to and under the Receivables, together with all Related Security and Collections with respect thereto and all Proceeds of the foregoing, to secure the rights of the Buyer set forth in this Agreement or as such rights may be determined in accordance with applicable law and the performance and payment of all indebtedness, obligations and liabilities of such Originator to the Buyer arising hereunder, including without limitation any liabilities arising from any breach by such Originator of any of its representations and warranties in the first sentence of Section 4.1(c) hereof (and any breach by such Originator of any of its representations and warranties in the first sentence of Section 4.1(c) hereof with respect to the conveyance of any particular Receivable shall be deemed to occur as of the time of such conveyance). Any such security interest in any Receivable granted to the Buyer under this Section 2.1(d) shall survive the sale and assignment of such Receivable pursuant to Section 2.1(a) of this Agreement and shall not be merged with the Buyer’s other rights, titles or interests in, to or under such property.

(e) To the extent that any software used by any Originator to account for the Receivables originated by it is non-transferable, such Originator hereby grants to each of Buyer,

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the Administrative Agent and the Servicers an irrevocable, non-exclusive license to use, without royalty or payment of any kind, all such software used by such Originator to account for such Receivables, to the extent necessary to administer such Receivables, whether such software is owned by such Originator or is owned by others and used by such Originator under license agreements with respect thereto; provided that should the consent of any licensor of such software be required for the grant of the license described herein to be effective, such Originator hereby agrees that upon the request of Buyer (or the Administrative Agent), such Originator will use its reasonable efforts to obtain the consent of such third-party licensor. If any software used by any Originator to account for the Receivables originated by it prohibits such Originator from granting the license to use described herein, or if, after reasonable efforts, consent of any licensor of such software for the grant of the license described herein is not obtained, there shall be no transfer of such software hereunder or any grant by such Originator of the license to use described herein. The license granted hereby shall be irrevocable until the later to occur of (i) indefeasible payment in full of the Aggregate Unpaids, and (ii) the date each of this Agreement and the Receivables Purchase Agreement terminates in accordance with its terms. Each Originator (A) shall take such action reasonably requested by Buyer and/or the Administrative Agent, from time to time hereafter, that may be necessary or appropriate to ensure that Buyer and its assigns have an enforceable ownership interest in the Records relating to the Receivables purchased from such Originator hereunder, and (B) shall use its reasonable efforts to ensure that each of the Buyer, the Administrative Agent and the Servicers has an enforceable right (whether by license or sublicense or otherwise) to use all of the computer software used to account for such Receivables and/or to recreate such Records.

Section 2.2 Servicing of Receivables .

In connection with the consummation of the sales provided for in this Agreement, each Originator hereby assigns and transfers to Buyer and Buyer’s assignees all of such Originator’s right, title and interest in and to each Lock-Box Account, and such Originator relinquishes all power to transfer, possess and control the Lock-Box Accounts and the contents thereof (except any powers with respect to the Lock-Box Accounts and contents thereof that are granted to such Originator in its capacity as Collection Agent). Each Originator agrees to perform all servicing of Receivables originated by it for the Buyer and its transfers and assigns pursuant to the terms of the Receivables Purchase Agreement. Each Originator shall hold in trust for the Buyer all Records which evidence or relate to its Receivables or Related Security, Collections or Proceeds with respect thereto.

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ARTICLE III

CONSIDERATION AND PAYMENT; REPORTING

Section 3.1 Purchase Price .

The purchase price for the Receivables and related property conveyed to the Buyer by each Originator under this Agreement on any Business Day shall be a dollar amount equal to the product of (a) the aggregate Outstanding Balance of the Receivables sold on such Business Day and (b) one minus the then applicable Discount Percentage (the “Purchase Price” ).

Section 3.2 Payment of Purchase Price .

(a) The Purchase Price for Receivables sold by an Originator on any Business Day shall be paid either (i) in cash to the extent funds are available therefor in excess of necessary working capital or (ii) if Buyer does not have sufficient cash to pay the Purchase Price, by means of (A) an advance under the applicable Subordinated Note (each, an “Advance” ) and/or (B) with the consent of the applicable Originator, treating a portion of the Purchase Price as capital contributed by such Originator to Buyer or (iii) with the consent of the applicable Originator, any combination of the foregoing applicable to such Originator. In the event Buyer does not have sufficient cash to pay the Purchase Price due with respect to any sale of Receivables hereunder (and solely in the case of Caremark, Caremark is not willing to consent to the treatment of such insufficiency as a capital contribution), such insufficiency shall be evidenced by the making of an Advance in an original principal amount equal to such cash shortfall owed to such Originator; provided, however, that no Originator shall make an Advance to Buyer to the extent that the aggregate amount of outstanding Advances from all Originators would be an amount such that the net worth of the Buyer would be less than $60,850,000 (the “Advance Limit” ). No sales of Receivables hereunder shall be made on or after the Purchase Termination Date. On the date of the initial purchase from each Originator of Receivables hereunder, the net worth of the Buyer shall be at least $60,850,000.

(b) All Advances made by each Originator to Buyer shall be evidenced by a single subordinated note, duly executed by Buyer in favor of such Originator, in substantially the form of Exhibit A annexed hereto, delivered on such Originator’s Effective Date and payable to such Originator in a principal amount equal to the Advance Limit thereunder (each, as amended, supplemented or otherwise modified and in effect from time to time, a “Subordinated Note” ). Each Originator is hereby authorized by Buyer to endorse on the schedule attached to its Subordinated Note (or a continuation of such schedule attached thereto and made a part thereof) an appropriate notation evidencing the date and amount of each Advance made by such Originator, as well as the date and amount of each payment made by the Buyer with respect thereto; provided , however , that the failure of any Person to make such a notation shall not affect any obligations of Buyer thereunder. Any such notation shall be conclusive and binding as to the date and amount of such Advance, or payment of principal or interest thereon, absent manifest error.

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(c) The terms and conditions of each Subordinated Note and all Advances thereunder shall be as follows:

(i) Repayment of Advances . All amounts paid by the Buyer with respect to the Advances shall be allocated first to the repayment of accrued interest until all such interest is paid, and then to the outstanding principal amount of the Advances. Subject to the provisions of this Agreement, the Buyer may borrow, repay and reborrow Advances on and after the date hereof and prior to the termination of this Agreement, subject to the terms, provisions and limitations set forth herein, including, without limitation, the requirement that no Advance be made to the extent that after giving effect thereto the aggregate outstanding principal amount of all Advances would exceed the Advance Limit.

(ii) Interest . Each Subordinated Note shall bear interest from its date on the outstanding principal balance thereof at a rate per annum equal to the Alternate Base Rate plus 2%, calculated as of the applicable Effective Date, as reset for each succeeding calendar month following March 2004 as the rate in effect as of the last Business Day of the calendar month immediately preceding such calendar month. Interest on each Advance shall be computed based on the number of days elapsed in a year of 360 days.

(iii) Subordination . The applicable Originator’s rights under its Subordinated Note shall be fully subordinated to any rights of the Administrative Agent, as agent for the Purchasers pursuant to the Receivables Purchase Agreement and the Asset Purchase Agreement, and shall not evidence any rights in the Receivables or related property.

(iv) Offsets, etc. The Buyer may offset any amount due and owing by the applicable Originator against any amount due and owing by Buyer to such Originator under the terms of its Subordinated Note.

Section 3.3 Settlement Report .

On each Settlement Date, each Originator shall deliver to the Buyer a monthly report, substantially in the form of Exhibit XI attached to the Receivables Purchase Agreement, showing, among other things, (a) the aggregate Purchase Price of Receivables sold by such Originator to the Buyer in the preceding month and (b) the aggregate Outstanding Balance of such Receivables that are Eligible Receivables.

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ARTICLE IV

REPRESENTATIONS AND WARRANTIES

Section 4.1 Each Originator’s Representations and Warranties .

As to itself and the Receivables originated by it, each Originator represents and warrants to the Buyer as of such Originator’s Effective Date and on each Business Day on which Receivables are sold by such Originator hereunder and after giving effect to each such sale:

(a) Existence and Power . Such Originator is a corporation or limited partnership, as the case may be, duly organized, validly existing and in good standing under the laws of its jurisdiction of incorporation or organization, and has all corporate or limited partnership power, as applicable, and all material governmental licenses, authorizations, consents and approvals required to carry on its business in each jurisdiction in which its business is now conducted, except where the failure to have such licenses, authorizations, consents and approvals is not reasonably likely to have a Material Adverse Effect. Such Originator is duly qualified to do business in, and is in good standing in, every other jurisdiction in which the nature of its business requires it to be so qualified, except where the failure to be so qualified or in good standing would not have a Material Adverse Effect.

(b) Company and Governmental Authorization; Contravention . The execution, delivery and performance by such Originator of the Transaction Documents to which it is a party are within such Originator’s corporate or limited partnership powers, as the case may be, have been duly authorized by all necessary corporate or partnership action, as applicable, require no action by or in respect of, or filing with, any government or political subdivision or any agency, authority, bureau, central bank, commission, department or instrumentality of any such government or political subdivision, or any court, tribunal, grand jury or arbitrator, in each case whether foreign or domestic, or official thereof (except for the filing of Uniform Commercial Code financing statements as required by this Agreement), and do not contravene, or constitute a default under, any provision of applicable law, rule or regulation or of the articles or certificate of incorporation or bylaws or the certificate of limited partnership or partnership agreement, as applicable, of such Originator or of any material agreement or instrument or any judgment, injunction, order, writ or decree binding upon such Originator and will not result in the creation or imposition of any Adverse Claim (except those created by this Agreement and the Receivables Purchase Agreement) on the assets of such Originator or any of its Subsidiaries except, in any case, where such contravention or default could not reasonably be expected to have a Material Adverse Effect.

(c) Valid and Perfected Sale; Binding Effect . Each purchase of Receivables and Related Security by the Buyer hereunder from such Originator shall constitute a valid and perfected sale and assignment by such Originator to the Buyer, enforceable against creditors of, and purchasers from, such Originator. Each of the Transaction Documents to which such Originator is a party constitutes the legal, valid and binding obligation of such Originator, enforceable in accordance with its terms, subject to applicable bankruptcy, insolvency, moratorium or other similar laws affecting the rights of creditors and general equitable principles (whether considered in a proceeding in equity or at law).

(d) Quality of Title . Immediately preceding the sale of the Receivables by such Originator and related property pursuant to this Agreement, such Originator was the owner of all of its Receivables, free and clear of any Adverse Claim. On or prior to such Originator’s Effective Date, all financing statements and other documents required to be recorded or filed in order to perfect and protect the interest of the Buyer in, to and under the Receivables originated by such Originator against all creditors of and purchasers from such Originator will have been duly filed in each filing office necessary for such purpose and all filing fees and filing taxes, if any, payable in connection with such filings shall have been paid in full.

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(e) Accuracy of Information . All information heretofore furnished by such Originator to the Buyer and the Administrative Agent for purposes of or in connection with this Agreement, any other Transaction Document, or any transaction contemplated hereby or thereby is, and all such information hereafter furnished by such Originator to the Buyer, the Administrative Agent, the Co-Agents or any of the Purchasers will be, true and correct in every material respect, on the date such information is stated or certified.

(f) Tax Status . Such Originator has filed all material tax returns (Federal, state and local) required to be filed by it and has paid or made adequate provision for the payment of all taxes, assessments and other governmental charges.

(g) Action, Suits . There are no actions, suits or proceedings pending, or to the knowledge of such Originator, threatened, against or affecting such Originator or its properties, in or before any court, arbitrator or other body, which are reasonably likely, individually or in the aggregate, to have a Material Adverse Effect.

(h) Place of Business . The principal place of business and chief executive office of such Originator are located at (i) in the case of Caremark, 2211 Sanders Road, Northbrook, Illinois 60062, and (ii) in the case of AdvancePCS, 9501 E. Shea Blvd., Scottsdale, AZ 85260. The offices where such Originator keeps all of the Records, are located at (A) in the case of Caremark, 2211 Sanders Road, Northbrook, Illinois 60062, or (B) in the case of AdvancePCS, 9501 E. Shea Blvd., Scottsdale, AZ 85260, or in such other locations notified to the Buyer by such Originator in accordance with this Agreement in jurisdictions where all action required by the terms of this Agreement has been taken and completed. In addition, Exhibit V of the Receivables Purchase Agreement lists the federal employer identification number and the organization identification number of such Originator.

(i) Solvency . Such Originator is not insolvent, does not have unreasonably small capital with which to carry on its business, is able to pay its debts generally as they become due and payable, and its liabilities do not exceed its assets.

(j) Tradenames, Etc. As of the date hereof: (i) such Originator has only the Subsidiaries and divisions listed on Exhibit V to the Receivables Purchase Agreement; and (ii) such Originator has, within the last five (5) years, operated only under the tradenames identified on Exhibit V to the Receivables Purchase Agreement, and, within the last five (5) years, such Originator has not changed its state of incorporation or organization, as the case may be, or its name, merged with or into or consolidated with any other Person or been the subject of any proceeding under Title 11, United States Code (Bankruptcy), except as disclosed in Exhibit V the Receivables Purchase Agreement.

(k) Nature of Receivables . Each Receivable originated by such Originator and included in any report delivered by such Originator pursuant to Section 3.3 hereof as an Eligible Receivable, was an Eligible Receivable on the date of its acquisition by Buyer hereunder.

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(l) Credit and Collection Policy . Since January 1, 2004, there has been no change in the Credit and Collection Policy which could have a Material Adverse Effect. Such Originator has complied in all material respects with its Credit and Collection Policy with regard to each Receivable originated by it and the related Contract, and has not made any change to such Credit and Collection Policy, except such material change as to which Buyer (or its assigns) has been notified in accordance with the Receivables Purchase Agreement. Since such date, no change has occurred in the overall rate of collection of the Receivables which could have a Material Adverse Effect.

(m) Collections and Servicing . Since January 1, 2004, there has been no change in the ability of such Originator to service and collect its Receivables which has had or is reasonably likely to have a Material Adverse Effect.

(n) Binding Effect of Receivables and Contract . Each Receivable originated by such Originator and related Contract constitutes a legal, valid and binding obligation of the Obligor, enforceable against the Obligor in accordance with its terms, subject to the effect of bankruptcy, insolvency, reorganization or similar laws affecting creditors’ rights generally (whether considered in a proceeding at law or in equity).

(o) Not a Holding Company or an Investment Company . Such Originator is not a “ holding company ” or a “ subsidiary holding company ” of a “ holding company ” within the meaning of the Public Utility Holding Company Act of 1935, as amended, or any successor statute. Such Originator is not an “ investment company ” within the meaning of the Investment Company Act of 1940, as amended (the “Act” ), or any successor statute.

(p) ERISA . Each of such Originator and its ERISA Affiliates is in compliance in all material respects with ERISA, and no lien exists in favor of the Pension Benefit Guaranty Corporation on any of the Receivables.

(q) Lock-Box Accounts . The names and addresses of all the Lock-Box Banks, together with the account numbers of the Lock-Box Accounts at such Lock-Box Banks, are specified in Exhibit VI to the Receivables Purchase Agreement. All Obligors have been instructed to make payment to a Lock-Box Account.

(r) Bulk Sales . No transaction contemplated by this Agreement requires compliance with any bulk sales act or similar law.

(s) Brokers . No broker or finder acting on behalf of such Originator or any Affiliate of such Originator was employed or utilized in connection with this Agreement or the Receivables Purchase Agreement or the transactions contemplated hereby or thereby and neither such Originator nor any Affiliate of such Originator has any obligation to any Person in respect of any finder’s or brokerage fees in connection therewith.

(t) Use of Proceeds . No proceeds of any sale by such Originator will be used by such Originator (i) for a purpose that violates, or would be inconsistent with, Regulation T, U or

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