42 CFR § 410.3 - Scope of benefits.
(a) Covered services. The SMI program helps pay for the following:
(1) Medical and other health services such as physicians' services, outpatient services furnished by a hospital or a CAH, diagnostic tests, outpatient physical therapy and speech pathology services, rural health clinic services, Federally qualified health center services, IHS, Indian tribe, or tribal organization facility services, and outpatient renal dialysis services.
(2) Services furnished by ambulatory surgical centers (ASCs), home health agencies (HHAs), comprehensive outpatient rehabilitation facilities (CORFs), and partial hospitalization services provided by community mental health centers (CMHCs).
(b) Limitations on amount of payment.
(1) Medicare Part B does not pay the full reasonable costs or charges for all covered services. The beneficiary is responsible for an annual deductible and a blood deductible and, after the annual deductible has been satisfied, for coinsurance amounts specified for most of the services.