[remainder of pageintentionally blank]

Exhibit 4.3

ADDITIONAL AUTHORIZED REPRESENTATIVE JOINDER AGREEMENT, dated as of June 3, 2016 (this “Joinder Agreement”), among the Additional Authorized Representative (as defined below), the Existing Authorized Representative (as defined below), Universal Health Services, Inc. (the “Borrower”), the other Grantors party hereto, and JPMorgan Chase Bank, N.A., as Collateral Agent (in such capacity, the “Collateral Agent”), as collateral agent for the Secured Parties.

Capitalized terms used herein but not otherwise defined herein shall have the meanings assigned to such terms in the Amended and Restated Collateral Agreement, dated as of August 7, 2014, by and among the Borrower, the other Grantors party thereto, the Authorized Representatives and Collateral Agent (as amended, restated, modified, and/or supplemented from time to time, the “Collateral Agreement”).

The Companies and the other Grantors propose to issue or incur “Additional Lien Obligations” designated by the Borrower as such in accordance with Section 9 of the Collateral Agreement in an officers’ certificate delivered concurrently herewith to the Collateral Agent and the Authorized Representatives (the “Additional Lien Obligations”).

The Person identified in the signature pages hereto as the “Additional Authorized Representative” (the “Additional Authorized Representative”) will serve as the administrative agent, trustee or a similar representative for the holders of the Additional Lien Obligations with respect to the Borrower’s 5.000% Senior Secured Notes due 2026 (such holders constituting “Additional Lien Secured Parties”).

The Additional Authorized Representative wishes, in accordance with the provisions of the Collateral Agreement, to become a party to the Collateral Agreement and to acquire and undertake, for itself and on behalf of such Additional Lien Secured Parties, the rights and obligations of an “Additional Authorized Representative” and “Secured Parties” thereunder.

The 2014 Trustee, as Authorized Representative for the existing 2022 Senior Notes and existing holders of the 2022 Senior Notes (in such capacity, the “Existing Authorized Representative”) wishes to confirm that it will act in such capacity for the holders of the additional 2022 Senior Notes being issued on the date hereof (the “Additional 2022 Senior Notes”).

Accordingly, the Additional Authorized Representative (for itself and on behalf of its Additional Lien Secured Parties), the Existing Authorized Representative (for itself and the holders of the 2022 Senior Notes), the Borrower and the other Grantors agree as follows, for the benefit of the Collateral Agent, the existing Authorized Representatives and the existing Secured Parties:

SECTION 1.01. Accession to the Collateral Agreement. The Additional Authorized Representative hereby (a) accedes and becomes a party to the Collateral Agreement as an “Additional Authorized Representative,” (b) agrees, for itself and on behalf of its Additional Lien Secured Parties, to all the terms and provisions of the Collateral Agreement and (c) acknowledges and agrees that (i) the Additional Lien Obligations with respect to the Borrower’s 5.000% Senior Secured Notes due 2026 and Liens on any Common Collateral securing the same shall be subject to the provisions of the Collateral Agreement and (ii) the Additional Authorized Representative and such Additional Lien Secured Parties shall have the rights and obligations specified under the Collateral Agreement with respect to an “Authorized Representative” or a “Secured Party,” and shall be subject to and bound by the provisions of the Collateral Agreement.

SECTION 1.02. Representations and Warranties of the Additional Authorized Representative. The Additional Authorized Representative represents and warrants to the Collateral

Agent, the existing Authorized Representatives and the existing Secured Parties that (a) it has full power and authority to enter into this Joinder Agreement, in its capacity as the Additional Authorized Representative, (b) this Joinder Agreement has been duly authorized, executed and delivered by it and constitutes its legal, valid and binding obligation, enforceable against it in accordance with its terms, and (c) the Additional Lien Documents relating to the Additional Lien Obligations with respect to the Borrower’s 5.000% Senior Secured Notes due 2026 provide that, upon the Additional Authorized Representative’s execution and delivery of this Joinder Agreement, (i) such Additional Lien Obligations and liens on any Common Collateral securing the same shall be subject to the provisions of the Collateral Agreement and (ii) the Additional Authorized Representative and its Additional Lien Secured Parties shall have the rights and obligations specified therefor under, and shall be subject to and bound by the provisions of, the Collateral Agreement.

SECTION 1.03. Confirmation of Existing Authorized Representative. By signing below, the Existing Authorized Representative agrees and confirms that (i) it is acting as Authorized Representative on behalf of the Additional 2022 Senior Notes and the holders of the Additional 2022 Senior Notes on the same basis that it is so acting for the existing 2022 Senior Notes and existing holders of the existing 2022 Senior Notes and (ii) the Additional 2022 Senior Notes shall be “2022 Senior Notes” under the Collateral Agreement and shall be subject to the same terms and provisions as the existing “2022 Senior Notes” under the Collateral Agreement. For the avoidance of doubt, the Existing Authorized Representative agrees and confirms that the Additional 2022 Senior Notes shall form a single class and shall constitute the same “Series” as the existing 2022 Senior Notes for all purposes under the Collateral Agreement and the 2014 Indenture.

SECTION 1.04. Parties in Interest. This Joinder Agreement shall be binding upon and inure to the benefit of the parties hereto and their respective successors and assigns, as well as the other Secured Parties, all of whom are intended to be bound by, and to be third-party beneficiaries of, this Agreement.

SECTION 1.05. Counterparts. This Joinder Agreement may be executed in counterparts, each of which shall constitute an original but all of which when taken together shall constitute a single contract. Delivery of an executed signature page to this Joinder Agreement by facsimile or other electronic transmission shall be as effective as delivery of a manually signed counterpart of this Joinder Agreement.

SECTION 1.06. Governing Law. This Joinder Agreement shall be construed in accordance with and governed by the law of the State of New York.

SECTION 1.07. Notices. All communications and notices hereunder shall be in writing and given as provided in Section 8.2 of the Collateral Agreement. All communications and notices hereunder to the Additional Authorized Representative shall be given to it at the address set forth under its signature hereto, which information supplements Section 8.2 to the Collateral Agreement.

SECTION 1.08. Expenses. The Borrower and the other Grantors, jointly and severally, agree to reimburse the Collateral Agent and each of the Authorized Representatives for its reasonable out-of-pocket expenses in connection with this Joinder Agreement, including the reasonable fees, other charges and disbursements of counsel for the Collateral Agent and any of the Authorized Representatives.

[remainder of page intentionally blank]

IN WITNESS WHEREOF, the Additional Authorized Representative, the Existing Authorized Representative, the Borrower and the other Grantors have duly executed this Joinder Agreement to the Collateral Agreement as of the day and year first above written.

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]

[Signature Page for Additional Authorized Representative Joinder Agreement]