42 CFR §411.51

1. (a)The beneficiary is responsible for taking whatever action is necessary to obtain any payment that can reasonably be expected under no-fault insurance.
2. (b)Except as specified in § 411.53, Medicare does not pay until the beneficiary has exhausted his or her remedies under no-fault insurance.
3. (c)Except as specified in § 411.53, Medicare does not pay for services that would have been covered by the no-fault insurance if the beneficiary had filed a proper claim.
4. (d)However, if a claim is denied for reasons other than not being a proper claim, Medicare pays for the services if they are covered under Medicare.