42 C.F.R. § 411.46 – Lump-sum payments.

(a) Lump-sum commutation of future benefits. If a lump-sum compensation award stipulates that the amount paid is intended to compensate the individual for all future medical expenses required because of the work-related injury or disease, Medicare payments for such services are excluded until medical expenses related to the injury or disease equal the amount of the lump-sum payment.
(b) Lump-sum compromise settlement.
1. (1) A lump-sum compromise settlement is deemed to be a workers' compensation payment for Medicare purposes, even if the settlement agreement stipulates that there is no liability under the workers' compensation law or plan.
2. (2) If a settlement appears to represent an attempt to shift to Medicare the responsibility for payment of medical expenses for the treatment of a work-related condition, the settlement will not be recognized. For example, if the parties to a settlement attempt to maximize the amount of disability benefits paid under workers' compensation by releasing the workers' compensation carrier from liability for medical expenses for a particular condition even though the facts show that the condition is work-related, Medicare will not pay for treatment of that condition.
(c) Lump-sum compromise settlement: Effect on services furnished before the date of settlement. Medicare pays for medical expenses incurred before the lump-sum compromise settlement only to the extent specified in § 411.47.
(d) Lump-sum compromise settlement: Effect on payment for services furnished after the date of settlement—(1) Basic rule. Except as specified in paragraph (d)(2) of this section, if a lump-sum compromise settlement forecloses the possibility of future payment of workers' compensation benefits, medical expenses incurred after the date of the settlement are payable under Medicare.
(2) Exception. If the settlement agreement allocates certain amounts for specific future medical services, Medicare does not pay for those services until medical expenses related to the injury or disease equal the amount of the lump-sum settlement allocated to future medical expenses.