42 CFR §417.122

1. (a)Liability protection.
   1. (1)Each HMO must adopt and maintain arrangements satisfactory to CMS to protect its enrollees from incurring liability for payment of any fees that are the legal obligation of the HMO. These arrangements may include any of the following:
      1. (i)Contractual arrangements that prohibit health care providers used by the enrollees from holding any enrollee liable for payment of any fees that are the legal obligation of the HMO.
      2. (ii)Insurance, acceptable to CMS.
      3. (iii)Financial reserves, acceptable to CMS, that are held for the HMO and restricted for use only in the event of insolvency.
      4. (iv)Any other arrangements acceptable to CMS.
   2. (2)The requirements of this paragraph do not apply to an HMO if CMS determines that State law protects the HMO enrollees from liability for payment of any fees that are the legal obligation of the HMO.
2. (b)Protection against loss of benefits if the HMO becomes insolvent. The insolvency protection plan required under § 417.120(a) must provide for continuation of benefits as follows:
   1. (1)For all enrollees, for the duration of the contract period for which payment has been made.
   2. (2)For enrollees who are in an inpatient facility on the date of insolvency, until they are discharged from the facility.