4 CFR 83.9 - Social Security number.
(a) GAO may not require individuals to disclose their Social Security Number (SSN) unless disclosure would be required—
(2) Under any statute, executive order, or regulation that authorizes any Federal, State, or local agency maintaining a system of records that was in existence and operating prior to January 1, 1975, to request the SSN as a necessary means of verifying the identity of an individual.
(b) Individuals asked to voluntarily provide their SSN shall suffer no penalty or denial of benefits for refusing to provide it.
Title 4 published on 2013-01-01.
No entries appear in the Federal Register after this date, for 4 CFR Part 83.