N.J. Stat. § 30:9-27
Whenever a county establishes a hospital under section 30:9-24 of this title adjacent to or near a municipal hospital, the county and municipality in the management of the respective hospitals may render one for the other such services as they may by contract agree upon. Such contract shall be in writing and shall be executed by the governing bodies or chief executive officers of the contracting parties; may be for a fixed or indefinite term; and may from time to time be amended by the contracting parties.
Such contract shall fix or regulate the cost to be paid for such services; by whom to be paid; shall specify the duties to be performed by each of the contracting parties and shall contain such other provisions as the contracting parties may deem necessary. For the purpose of carrying the contract into effect, the contracting parties may acquire and hold in common any personal property useful or necessary in its proper execution.
N.J.S. § 30:9-27