FOURTH AMENDED AND RESTATED RECEIVABLES SALES AGREEMENT Execution Version FOURTH AMENDED AND RESTATED RECEIVABLES SALE AGREEMENT dated as of

FOURTH AMENDED AND RESTATED RECEIVABLES

dated as of October 28, 2015

QUEST DIAGNOSTICS INCORPORATED AND EACH

OF ITS DIRECT OR INDIRECT SUBSIDIARIES WHO IS OR HEREAFTER BECOMES A SELLER HEREUNDER,

QUEST DIAGNOSTICS RECEIVABLES INC.,

Amended AND RESTATED RECEIVABLES SALE AGREEMENT

AMENDED AND RESTATED RECEIVABLES SALE AGREEMENT (as amended, supplemented, restated or otherwise modified from time to

time, this "Agreement"), dated as of October 28, 2015 is entered into by and between:

(1) Quest Diagnostics

Incorporated, a Delaware corporation ("Quest Diagnostics"), Quest Diagnostics Nichols Institute, a California

corporation, Quest Diagnostics Incorporated, a Michigan corporation, Quest Diagnostics Incorporated, a Maryland corporation, Quest

Diagnostics LLC, a Connecticut limited liability company, Quest Diagnostics LLC, a Massachusetts limited liability company, Quest

Diagnostics of Pennsylvania Inc., a Delaware corporation, MetWest Inc., a Delaware corporation, Quest Diagnostics LLC, an Illinois

limited liability company, Quest Diagnostics Clinical Laboratories, Inc., a Delaware corporation, Unilab Corporation, a Delaware

corporation ("Unilab"), Quest Diagnostics Nichols Institute, Inc., a Virginia corporation ("Quest-Nichols"),

Quest Diagnostics Incorporated, a Nevada corporation ("Quest-Nevada"), LabOne, LLC, a Missouri limited

liability company ("LabOne"), ExamOne World Wide, Inc., a Pennsylvania corporation ("ExamOne"),

LabOne of Ohio, Inc., a Delaware corporation ("LabOne Ohio"), Specialty Laboratories, Inc., a California

corporation ("Specialty"), Solstas Lab Partners Group, LLC, a North Carolina limited liability company

("Solstas Group"), Solstas Lab Partners, LLC, a Virginia limited liability company ("Solstas"),

Summit Health, Inc., a Michigan corporation ("Summit"), Athena Diagnostics, Inc., a Delaware corporation

("Athena"), Focus Diagnostics Inc., a Delaware corporation ("Focus"), and MedPlus,

Inc., an Ohio corporation ("MedPlus"), and each of the other direct or indirect, subsidiaries of Quest

Diagnostics who hereafter becomes a party hereto by executing a joinder agreement in the form of Exhibit D hereto (each, a "Joinder

Agreement"), as sellers, and

(2) Quest Diagnostics

Receivables Inc., a Delaware corporation, as purchaser (the "Buyer"),

and amends and restates in its entirety

that certain Third Amended and Restated Receivables Sale Agreement, dated as of December 12, 2008, by and among the parties hereto

other than Solstas Group, Solstas, Summit, Athena, Focus and MedPlus (as heretofore amended and restated from time to time, the

"Existing Agreement").

indicated, capitalized terms used in this Agreement are defined in Annex A hereto

or, if not defined therein, in that certain Fifth Amended and Restated Credit and Security Agreement dated as of October 28, 2015,

by and among the Buyer, as borrower, Quest Diagnostics, as initial servicer, the Lenders and Co-Agents from time to time party

thereto, PNC Bank National Association, as LC Issuer, and The Bank of Tokyo-Mitsubishi UFJ, Ltd., as Administrative Agent, as amended,

supplemented, restated, joined or otherwise modified from time to time in accordance with the terms thereof (the "Credit

and Security Agreement").

W I T N E S S E T H :

Quest Diagnostics owns, directly or indirectly all or substantially all of the issued and outstanding Equity Interests of each

of the other Sellers;

the Buyer is a limited purpose corporation, all of the issued and outstanding Equity Interests of which are owned by Quest Diagnostics;

Quest Diagnostics contributed to the Buyer's capital all of its Receivables in existence as of the Initial Cut-Off

Date, together with all Related Assets associated therewith;

the Sellers desire to sell Private Receivables and the Related Assets with respect thereto and Participation Interests in Specified

Government Receivables and the Related Assets with respect thereto, in each case owned from time to time by the Sellers to the

Buyer, and the Buyer is willing, on the terms and subject to the conditions set forth herein, to purchase such Private Receivables,

Participation Interests and Related Assets from the Sellers;

the Buyer has pledged the Private Receivables, the Participation Interests and the Related Assets received from the Sellers

hereunder to secure its Obligations under the Credit and Security Agreement, including, without limitation, its obligations to

repay Loans made and draws under Letters of Credit issued thereunder; and

at the request of the Buyer and its assigns, Quest Diagnostics has agreed to continue to act as Servicer for the Private

Receivables and to act as Servicer for the Specified Government Receivables subject to Participation Interests, although Quest

Diagnostics has informed the Buyer and its assigns that it may, subject to their approval and to satisfaction of the Rating Agency

Condition, if required, transfer that function to an Affiliate;

in consideration of the premises and the mutual covenants herein contained, and for other good and valuable consideration, the

receipt and sufficiency of which is hereby acknowledged, the parties hereto agree as follows:

AMOUNTS AND TERMS OF THE PURCHASES

Section 1.2 Purchases

of Private Receivables and Participation Interests.

the Applicable Closing Date for each Seller that has not already sold or contributed Private Receivables and Related Assets or

Participation Interests and Related Assets under the Previous Agreements (including by operation of Section 1.1 of the Existing

Agreement), in consideration for the Purchase Price and upon the terms and subject to the conditions set forth herein, each such

Seller does hereby sell, assign, transfer, set-over and otherwise convey to the Buyer, without recourse (except to the extent expressly

provided herein), and the Buyer does hereby purchase from

such Seller, all of such Seller's right, title and interest in

and to such Seller's Initial Private Receivables and all Related Assets with respect thereto and such Seller's Initial

Participation Interests and all Related Assets with respect thereto.

each Business Day after each Seller's Applicable Closing Date and prior to the Sale Termination Date, in consideration for

the Purchase Price and upon the terms and subject to the conditions set forth herein, such Seller does hereby sell, assign, transfer,

set-over and otherwise convey to the Buyer, without recourse (except to the extent expressly provided herein), and the Buyer does

hereby purchase from such Seller, all of such Seller's right, title and interest in and to such Seller's Additional

Private Receivables and all Related Assets with respect thereto and such Seller's Additional Participation Interests and

all Related Assets with respect thereto.

(c) It is the intention

of the parties hereto that each conveyance of Private Receivables and Participation Interests made under this Agreement shall constitute

an outright "sale of accounts" (as such terms are used in Article 9 of the UCC) or other absolute transfer, which is

absolute and irrevocable and shall provide the Buyer with the full benefits of ownership of the Private Receivables, Participation

Interests and the associated Related Assets. Except for the Purchase Price Credits owed pursuant to Section 1.4, each conveyance

of Private Receivables and Participation Interests hereunder is made without recourse to the applicable Seller; provided,

however, that (i) each Seller shall be liable to the Buyer for all representations, warranties, covenants and indemnities

made by such Seller pursuant to the terms of the Transaction Documents to which such Seller is a party, and (ii) such conveyance

does not constitute and is not intended to result in an assumption by the Buyer or any assignee thereof of any obligation of such

Seller or any other Person arising in connection with the Participation Interests, the Private Receivables, the related Contracts,

and/or other Related Assets or any other obligations of such Seller. In view of the intention of the parties hereto that the conveyances

of Private Receivables and Participation Interests made hereunder shall constitute outright sales of such Private Receivables and

Participation Interests rather than loans secured thereby, each Seller agrees that it will, on or prior to its Applicable Closing

Date, mark its master data processing records relating to its Receivables with the following legend (or the substantive equivalent

DESCRIBED HEREIN, TOGETHER WITH CERTAIN RELATED ASSETS, ARE EITHER THE PROPERTY OF Quest

Diagnostics Receivables Inc. OR SUBJECT TO RIGHTS OF QUEST DIAGNOSTICS RECEIVABLES INC."

Upon the request of the Buyer or the

Administrative Agent, each Seller will file such financing or continuation statements, or amendments thereto or assignments thereof,

and such other instruments or notices, as may be necessary or appropriate to perfect and maintain the perfection of the Buyer's

ownership interest in the Private Receivables, the Participation Interests and the respective Related Assets or as the Buyer or

the Administrative Agent may reasonably request.

shall be deemed to preclude Quest Diagnostics from contributing to the Buyer's capital, in lieu of selling, Private Receivables

and Participation Interests in Specified Government Receivables, in each case originated by Quest Diagnostics together with the

Related Assets associated therewith, and any such contribution is made with the intention that each such contribution, if any,