Wiki MEDICARE: Accepting cash in lieu of billing

Anchorage, AK
Best answers
Wondering if anyone can assist-
I’m working for a clinic with several providers- many of whom have opted out of Medicare, meaning we are able to enter into a private contract with patients who would like to pay cash in lieu of submitting a claim to their insurance.
My question is this: The MDs who own and operate the practice have both opted out of Medicare, however we employ several PAs part time who work at varying clinics in area and are contracted with Medicare under other practice affiliations. While seeing patients within our clinic- can these PAs legally enter into a private contract with Medicare patients?