42 CFR §406.5

1. (a)Hospital insurance without premiums. Hospital insurance is available to most individuals without payment of a premium if they:
   1. (1)Are age 65 or over, or
   2. (2)Have received social security or railroad retirement disability benefits for 25 months; or
   3. (3)Have end-stage renal disease. Subpart B of this part explains the requirements such individuals must meet to obtain hospital insurance without premiums.
2. (b)Premium hospital insurance. Many individuals who are age 65 or over, but do not meet the requirements set forth in subpart B of this part, and certain individuals under age 65, may obtain the benefits by paying a premium. Section 406.20 of this part explains the requirements individuals must meet to obtain premium hospital insurance.