42 CFR 457.515: Co-payments, coinsurance, deductibles, or similar cost-sharing charges: State plan requirements.

To impose copayments, coinsurance, deductibles or similar charges on enrollees, the State plan must describe—

(a) The service for which the charge is imposed;

(b) The amount of the charge;

(c) The group or groups of enrollees that may be subject to the cost-sharing charge;

(d) The consequences for an enrollee who does not pay a charge, and the disenrollment protections adopted by the State in accordance with § 457.570;

(e) The methodology used to ensure that total cost-sharing liability for a family does not exceed the cumulative cost-sharing maximum specified in § 457.560; and

(f) An assurance that enrollees will not be held liable for cost-sharing amounts for emergency services that are provided at a facility that does not participate in the enrollee's managed care network beyond the copayment amounts specified in the State plan for emergency services as defined in § 457.10.