The Social Security Act requires that the total family benefits of a disability beneficiary be reduced for receipt of certain public disability benefits (such as Workers' Compensation). Section 224(f) of the Act further requires a benefit redetermination effective for January of the third year after the year when the reduction was first required, and triennially thereafter.

Redetermination of such benefits depends on the average wage index—the same index used to compute Social Security benefits under sections 215(a) and (b) of the Social Security Act. In a redetermination, ratios of such average wage indexes are applied to a beneficiary's "average current earnings."

Ratios used to redetermine benefits are provided in tables for a selected year

Below, select the year (called the offset year) in which the benefit is first reduced.