42 CFR § 435.910 - Use of social security number.
(a) Except as provided in paragraph (h) of this section, the agency must require, as a condition of eligibility, that each individual (including children) seeking Medicaid furnish each of his or her Social Security numbers (SSN).
(b) The agency must advise the applicant of—
(1) [Reserved]
(2) The statute or other authority under which the agency is requesting the applicant's SSN; and
(3) The uses the agency will make of each SSN, including its use for verifying income, eligibility, and amount of medical assistance payments under §§ 435.940 through 435.960.
(c)-(d) [Reserved]
(e) If an applicant cannot recall his SSN or SSNs or has not been issued a SSN the agency must—
(1) Assist the applicant in completing an application for an SSN;
(2) Obtain evidence required under SSA regulations to establish the age, the citizenship or alien status, and the true identity of the applicant; and
(3) Either send the application to SSA or, if there is evidence that the applicant has previously been issued a SSN, request SSA to furnish the number.
(f) The agency must not deny or delay services to an otherwise eligible individual pending issuance or verification of the individual's SSN by SSA or if the individual meets one of the exceptions in paragraph (h) of this section.
(g) The agency must verify the SSN furnished by an applicant or beneficiary with SSA to ensure the SSN was issued to that individual, and to determine whether any other SSNs were issued to that individual.
(h) Exception.
(1) The requirement of paragraph (a) of this section does not apply and a State may give a Medicaid identification number to an individual who—
(i) Is not eligible to receive an SSN;
(ii) Does not have an SSN and may only be issued an SSN for a valid non-work reason in accordance with 20 CFR 422.104; or
(iii) Refuses to obtain an SSN because of well-established religious objections.
(2) The identification number may be either an SSN obtained by the State on the applicant's behalf or another unique identifier.
(3) The term well established religious objections means that the applicant—
(i) Is a member of a recognized religious sect or division of the sect; and
(ii) Adheres to the tenets or teachings of the sect or division of the sect and for that reason is conscientiously opposed to applying for or using a national identification number.
(4) A State may use the Medicaid identification number established by the State to the same extent as an SSN is used for purposes described in paragraph (b)(3) of this section.