42 C.F.R. § 438.106 : Public Health — CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES — MEDICAL ASSISTANCE PROGRAMS — MANAGED CARE — ENROLLEE RIGHTS AND PROTECTIONS — Liability for payment

Each MCO, PIHP, and PAHP must provide that its Medicaid enrollees are not held liable for any of the following:

(a) The MCO's, PIHP's, or PAHP's debts, in the event of the entity's insolvency.
(b) Covered services provided to the enrollee, for which-
(1) The State does not pay the MCO, PIHP, or PAHP; or
(2) The State, or the MCO, PIHP, or PAHP does not pay the individual or health care provider that furnished the services under a contractual, referral, or other arrangement.
(c) Payments for covered services furnished under a contract, referral, or other arrangement, to the extent that those payments are in excess of the amount that the enrollee would owe if the MCO, PIHP, or PAHP covered the services directly.

42 C.F.R. §438.106

81 FR 27852, 5/6/2016