42 U.S.C. § 1395g

The Secretary shall periodically determine the amount which should be paid under this part to each provider of services with respect to the services furnished by it, and the provider of services shall be paid, at such time or times as the Secretary believes appropriate (but not less often than monthly) and prior to audit or settlement by the Government Accountability Office, from the Federal Hospital Insurance Trust Fund, the amounts so determined, with necessary adjustments on account of previously made overpayments or underpayments; except that no such payments shall be made to any provider unless it has furnished such information as the Secretary may request in order to determine the amounts due such provider under this part for the period with respect to which the amounts are being paid or any prior period.

section 1395x(w)(2) of this titlesection 1395x(w)(2) of this titleNo payment shall be made to a provider of services which is a hospital for or with respect to services furnished by it for any period with respect to which it is deemed, under , to have in effect an arrangement with a quality improvement organization for the conduct of utilization review activities by such organization unless such hospital has paid to such organization the amount due (as determined pursuant to such section) to such organization for the review activities conducted by it pursuant to such arrangements or such hospital has provided assurances satisfactory to the Secretary that such organization will promptly be paid the amount so due to it from the proceeds of the payment claimed by the hospital. Payment under this subchapter for utilization review activities provided by a quality improvement organization pursuant to an arrangement or deemed arrangement with a hospital under shall be calculated without any requirement that the reasonable cost of such activities be apportioned among the patients of such hospital, if any, to whom such activities were not applicable.

No payment which may be made to a provider of services under this subchapter for any service furnished to an individual shall be made to any other person under an assignment or power of attorney; but nothing in this subsection shall be construed (1) to prevent the making of such a payment in accordance with an assignment from the provider if such assignment is made to a governmental agency or entity or is established by or pursuant to the order of a court of competent jurisdiction, or (2) to preclude an agent of the provider of services from receiving any such payment if (but only if) such agent does so pursuant to an agency agreement under which the compensation to be paid to the agent for his services for or in connection with the billing or collection of payments due such provider under this subchapter is unrelated (directly or indirectly) to the amount of such payments or the billings therefor, and is not dependent upon the actual collection of any such payment.

March 27, 2020section 1320b–5(g)(1)(B) of this titleWhenever a final determination is made that the amount of payment made under this part to a provider of services was in excess of or less than the amount of payment that is due, and payment of such excess or deficit is not made (or effected by offset) within 30 days of the date of the determination, interest shall accrue on the balance of such excess or deficit not paid or offset (to the extent that the balance is owed by or owing to the provider) at a rate determined in accordance with the regulations of the Secretary of the Treasury applicable to charges for late payments (or, in the case of such a determination made with respect to a payment made on or after , and during the emergency period described in under the program under subsection (e)(3), including such program as expanded pursuant to subsection (f), at a rate of 4 percent).