Mass. Gen. Laws ch. 18 § 33
The department shall require applicants or recipients of cash assistance to provide their social security number upon application; provided, however, that this section shall not apply to recipients who are present in the United States under 1 of the eligible noncitizen statuses as described in 106 CMR 203.675(A) or 106 CMR 320.620(A) or a victim of domestic violence who has a pending petition for legal status under the federal Violence Against Women Act; provided further, that the department shall provide a 3 month placeholder social security number for applicants or recipients who are expecting mothers in the third trimester of pregnancy or a child under 4 months of age. Failure to provide a valid social security number within 3 months shall result in the suspension of benefits until a valid social security number is provided and verified by the department. The department shall promulgate regulations in accordance with this section.
Mass. Gen. Laws ch. 18, § 33