20 C.F.R. § 404.204

(a) General. We compute most workers' primary insurance amounts under one of two major methods. There are, in addition, several special methods of computing primary insurance amounts which we apply to some workers. Your primary insurance amount is the highest of all those computed under the methods for which you are eligible.

(b) Major methods. (1) If after 1978 you reach age 62, or become disabled or die before age 62, we compute your primary insurance amount under what we call the average-indexed-monthly-earnings method, which is described in §§ 404.210 through 404.212. The earliest of the three dates determines the computation method we use.

(2) If before 1979 you reached age 62, became disabled, or died, we compute your primary insurance amount under what we call the average-monthly-wage method, described in §§ 404.220 through 404.222.

(c) Special methods. (1) Your primary insurance amount, computed under any of the special methods for which you are eligible as described in this paragraph, may be substituted for your primary insurance amount computed under either major method described in paragraph (b) of this section.

(2) If you reach age 62 during the period 1979-1983, your primary insurance amount is guaranteed to be the highest of—

(i) The primary insurance amount we compute for you under the average-indexed-monthly-earnings method;

(ii) The primary insurance amount we compute for you under the average-monthly-wage method, as modified by the rules described in §§ 404.230 through 404.233; or

(iii) The primary insurance amount computed under what we call the old-start method; as described in §§ 404.240 through 404.242.

(3) If you had all or substantially all of your social security earnings before 1951, we will also compute your primary insurance amount under what we call the old-start method.

(4) We compute your primary insurance amount under the rules in §§ 404.250 through 404.252, if—

(i) You were disabled and received social security disability insurance benefits sometime in your life;

(ii) Your disability insurance benefits were terminated because of your recovery or because you engaged in substantial gainful activity; and

(iii) You are, after 1978, re-entitled to disability insurance benefits, or entitled to old-age insurance benefits, or have died.

(5) In some situations, we use what we call a special minimum computation, described in §§ 404.260 through 404.261, to find your primary insurance amount. Computations under this method reflect long-term, low-wage attachment to covered work.