38 CFR § 1.575 - Social security numbers in veterans' benefits matters.
(a) Except as provided in paragraph (b) of this section, no one will be denied any right, benefit, or privilege provided by law because of refusal to disclose to the Department of Veterans Affairs a social security number.
(b) VA shall require mandatory disclosure of a claimant's or beneficiary's social security number (including the social security number of a dependent of a claimant or beneficiary) on necessary forms as prescribed by the Secretary as a condition precedent to receipt or continuation of receipt of compensation or pension payable under the provisions of chapters 11, 13 and 15 of title 38, United States Code, provided, however, that a claimant shall not be required to furnish VA with a social security number for any person to whom a social security number has not been assigned. VA may also require mandatory disclosure of an applicant's social security number as a condition for receiving loan guaranty benefits and a social security number or other taxpayer identification number from existing direct and vendee loan borrowers and as a condition precedent to receipt of a VA-guaranteed loan, direct loan or vendee loan, under chapter 37 of title 38, United States Code. (Pub. L. 97–365, sec. 4)
(c) A person requested by VA to disclose a social security number shall be told, as prescribed by § 1.578(c), whether disclosure is voluntary or mandatory. The person shall also be told that VA is requesting the social security number under the authority of title 38 U.S.C., or in the case of existing direct or vendee loan borrowers, under the authority of 26 U.S.C. 6109(a) in conjunction with sections 145 and 148 of Pub. L. 98–369, or in the case of loan applicants, under the authority of section 4 of Pub. L. 97–365. The person shall also be told that it will be used in the administration of veterans' benefits in the identification of veterans or persons claiming or receiving VA benefits and their records, that it may be used in making reports to the Internal Revenue Service where required by law, and to determine whether a loan guaranty applicant has been identified as a delinquent taxpayer by the Internal Revenue Service, and that such taxpayers may have their loan applications rejected, and that it may be used to verify social security benefit entitlement (including amounts payable) with the Social Security Administration and, for other purposes where authorized by both title 38 U.S.C., and the Privacy Act of 1974, (Pub. L. 93–579), or, where required by another statute. (Pub. L. 97–365, sec. 4)
(d) A document the Department sends by mail may not include the social security number of an individual except as provided below:
(1) The social security number must be truncated to no more than the last four digits; or
(2) If truncation of the social security number is not feasible:
(i) The Senior Agency Official for Privacy, the Chief Privacy Officer, and the Social Security Number Advisory Board (SSNAB) must jointly determine that inclusion of the social security number on the document is necessary as required by law; to comply with another legal mandate; to identify a specific individual where no adequate substitute is available; or to fulfill a compelling Department business need;
(ii) The document that includes the complete social security number of an individual must be listed on the Complete Social Security Number Mailed Documents Listing on a publicly available website; and
(iii) No portion of the social security number may be visible on the outside of any mailing.