(a) An individual who is automatically enrolled in SMI under §407.17 will have the month of enrollment determined in accordance with paragraphs (b) through (f) of this section. The month of enrollment determines the month of entitlement.

(b) An individual is automatically enrolled in the third month of the initial enrollment period if he or she—

(1) Is entitled to social security benefits under section 202 of the Act on the first day of the initial enrollment period;

(2) Is entitled to hospital insurance based on end-stage renal disease; on entitlement to disability benefits as a social security or railroad retirement beneficiary; or on deemed entitlement to disability benefits on the basis of Medicare-qualified government employment; or

(3) Establishes entitlement to hospital insurance by filing an application and meeting all other requirements (as set forth in subpart B of part 406 of this chapter) during the first 3 months of the initial enrollment period.

(c) If an individual establishes entitlement to hospital insurance on the basis of an application filed in the last 4 months of the SMI initial enrollment period, he or she is automatically enrolled for SMI in the month in which the application is filed.

(d) If an individual establishes entitlement to hospital insurance on the basis of an application filed after the SMI initial enrollment period but not during a general enrollment period in effect before April 1, 1981, or after September 30, 1981, he or she is automatically enrolled for SMI on the first day of the next general enrollment period.

(e) If the individual establishes entitlement to hospital insurance on the basis of an application filed during a SMI general enrollment period in effect before April 1, 1981 or after September 30, 1981, he or she is automatically enrolled on the first day of that period.

(f) If an individual established entitlement to hospital insurance on the basis of an application filed during the general enrollment period of April 1, 1981, through September 30, 1981, he or she was automatically enrolled for SMI on the first day of the month in which the application was filed.