1. Provision of the Social Security Act, Sections 1842(1) and 1879, that protects the patient from financial liability when Medicare denies or reduces payment for a service or item based on it being considered as ‘not reasonable and necessary’; under this provision, the patient may not be required to pay the provider for a service, if certain conditions are met. 2. In the Medicare program, provision that a beneficiary is not responsible to pay for a medical service if he or she was not informed that the service would not be covered by Medicare. Also see Advance Beneficiary Notice (ABN) .