42 CFR §411.404

1. (a)Basic rule. A beneficiary who receives services that constitute custodial care under § 411.15(g) or that are not reasonable and necessary under § 411.15(k), is considered to have known that the services were not covered if the criteria of paragraphs (b) and (c) of this section are met.
2. (b)Written notice.
   1. (1)Written notice is given to the beneficiary, or to someone acting on his or her behalf, that the services were not covered because they did not meet Medicare coverage guidelines.
   2. (2)A notice concerning similar or reasonably comparable services furnished on a previous occasion also meets this criterion.
   3. (3)After a beneficiary is notified that there is no Medicare payment for a service that is not covered by Medicare, he or she is presumed to know that there is no Medicare payment for any form of subsequent treatment for the non-covered condition.
3. (c)Source of notice. The notice was given by one of the following:
   1. (1)The QIO, intermediary, or carrier.
   2. (2)The group or committee responsible for utilization review for the provider that furnished the services.
   3. (3)The provider, practitioner, or supplier that furnished the service.