Good question. Yes FAR 28.102-1(b)(1)(iii) specifically authorizes the use of Tripartite Escrow Agreements. DFARS 228.102-1(1) implements different dollar values and authorizes any of the alternatives listed at FAR 28.102-1(b)(1).

Basically, a tripartite escrow agreement is when the prime contractor establishes an escrow account in a federally insured financial institution and enters into a tripartite escrow agreement with the financial institution, as escrow agent, and all of the suppliers of labor and material. The escrow agreement shall establish the terms of payment under the contract and of resolution of disputes among the parties. The Government makes payments to the contractor’s escrow account, and the escrow agent distributes the payments in accordance with the agreement; or triggers the disputes resolution procedures if required.

Not surprisingly (due to company names, signatures, etc.) we do not have a real sample.  There are many resources available to learn more about these and to see a template. Some of these are provided here:

https://tripartiteescrowagreements.com

http://tripartiteescrow.com/faq/#5

https://www.ipds.gov.in/Model_Documents/Escrow_Agreement_Template.pdf