(a) If your old-age benefits begin in the month you attain full retirement age (as defined in Sec. 404.409), your monthly benefit is equal to the primary insurance amount (as explained in subpart C of this part).
(b) If your old-age benefits begin after the month you attain full retirement age, your monthly benefit is your primary insurance amount plus an increase for retiring after full retirement age. See Sec. 404.313 for a description of these increases.
(c) If your old-age benefits begin before the month you attain full retirement age, your monthly benefit amount is the primary insurance amount minus a reduction for each month you are entitled before you attain full retirement age. These reductions are described in Secs. 404.410 through 404.413. [68 FR 4702, Jan. 30, 2003]