20 CFR 228.10: Computation of the tier I annuity component for a widow(er), disabled widow(er), remarried widow(er), and a surviving divorced spouse.

The tier I annuity component for these beneficiaries is generally based on the survivor tier I Primary Insurance Amount (PIA). The survivor tier I PIA is determined in accordance with section 215 of the Social Security Act using the deceased employee's combined railroad and social security earnings after 1950 (or after 1936 if a higher PIA would result) up to the maximum creditable amounts through the year of the employee's death. See part 225 of this chapter. This amount may be further adjusted for certain reductions or deductions as described in §§ 228.15-228.20 of this part and is subject to the family maximum. See § 228.14 of this part.