42 CFR § 417.456 - Refunds to Medicare enrollees.
(a) Definitions. As used in this section -
Amounts incorrectly collected means amounts collected that are in excess of those specified in § 417.452. It includes amounts collected when the enrollee was believed not entitled to Medicare benefits if the enrollee is later determined to have been entitled to Medicare benefits and CMS is liable for payments as specified in § 417.450.
(1) Emergency services;
(b) Basic commitment. An HMO or CMP must agree to refund all amounts incorrectly collected from its Medicare enrollees, or from others on behalf of the enrollees, and any other amounts due the enrollees or others on their behalf.
(c) Refund by lump sum payment. An HMO or CMP must make refunds to its current and former Medicare enrollees, or to others who have made payments on behalf of enrollees, by lump sum payment for the following:
(1) Incorrectly collected amounts that were not collected as premiums.
(2) Other amounts due.
(d) Refund by premium adjustment or lump sum payment or both. An HMO or CMP may make refund by adjustment of future premiums, by lump sum payment, or by a combination of both methods, for amounts that were incorrectly collected in the form of premiums or through a combination of premium payments and other charges.
(e) Refund when enrollee has died or cannot be located. If an enrollee has died or cannot be located after reasonable effort by the HMO or CMP, the HMO or CMP must make the refund in accordance with State law.
(f) Reduction by CMS. If the HMO or CMP does not make refund in accordance with paragraphs (b) through (d) of this section by the end of the contract period following the contract period during which an amount was determined to be due an enrollee, CMS reduces its payment to the HMO or CMP by the amounts incorrectly collected or otherwise due, and arranges for those amounts to be paid to the Medicare enrollee.