13 CFR 102.35 - Use and collection of Social Security Numbers.
Each Program/Support Office Head or designee shall ensure that collection and use of SSN is performed only when the functionality of the system is dependant on use of the SSN as an identifier. Employees authorized to collect information must be aware:
(a) That individuals may not be denied any right, benefit, or privilege as a result of refusing to provide their social security numbers, unless:
(1) The collection is authorized either by a statute; or
(2) The social security numbers are required under statute or regulation adopted prior to 1975 to verify the identity of an individual; and
(b) That individuals requested to provide their social security numbers must be informed of:
(1) Whether providing social security numbers is mandatory or voluntary;
(2) Any statutory or regulatory authority that authorizes the collection of social security numbers; and
(3) The uses that will be made of the numbers.