45 CFR § 205.52 - Furnishing of social security numbers.
(a) As a condition of eligibility, each applicant for or recipient of aid will be required:
(1) To furnish to the State or local agency a social security account number, hereinafter referred to as the SSN (or numbers, if more than one has been issued); and
(2) If he cannot furnish a SSN (either because such SSN has not been issued or is not known), to apply for such number through procedures adopted by the State or local agency with the Social Security Administration. If such procedures are not in effect, the applicant or recipient shall apply directly for such number, submit verification of such application, and provide the number upon its receipt.
(b) The State or local agency will assist the applicant or recipient in making applications for SSNs and will comply with the procedures and requirements established by the Social Security Administration for application, issuance, and verification of social security account numbers.
(c) The State or local agency will not deny, delay, or discontinue assistance pending the issuance or verfication of such numbers if the applicant or recipient has complied with the requirements of paragraph (a) of this section.
(e) “Applicant” and “recipient” include for the purposes of this section the individuals seeking or receiving assistance and any other individual whose needs are considered in determining the amount of assistance.
(f) The State or local agency shall notify the applicant or recipient that the furnishing of the SSN is a condition of eligibility for assistance required by section 1137 of the Social Security Act and that the SSN will be utilized in the administration of the program.
(g) The State agency will submit all unverified social security numbers to the Social Security Administration (SSA) for verification. The State agency may accept as verified a social security number provided directly to the State agency by SSA or by another Federal or federally-assisted benefit program which has received the number from SSA or has submitted it to SSA for verification.