Since a pair of 1938 Treasury Department Tax Rulings, and another in 1941, Social Security benefits have been explicitly excluded from federal income taxation. (A revision was issued in 1970, but it made no changes in the existing policy.)

There are three separate Treasury Rulings, two from 1938 and one from 1941. During the years 1937-1939 two types of Social Security benefit were paid: Lump-sum retirement payments to retired workers, and lump-sum death benefits to the family of deceased workers. So there are two 1938 tax rulings, one covering lump-sum retirement payments and one covering lump-sum death payments.

In 1939 the Social Security Act was amended and dramatically expanded to include survivors and dependents benefits of various types. Therefore, in a 1941 ruling, the Treasury Department explicitly extended its earlier rulings to these new types of benefits.

In 1970, the prior rulings were reaffirmed.