Ask your foster child’s social worker for the chid’s SSN if you need it to obtain important information or benefits. California law requires social workers to give the child’s social security number, if known, to the foster parent. Sometimes, you can easily locate the child’s SSN on documents about the child that you may have on hand. The SSN is to be contained in the written “caregiver placement agreement.” (WIC section 16503.5.) If the child’s biological parent(s) never obtained a SSN for the child, you can ask the social worker to help get the child a SSN by providing you with the original (not photocopies) of documents the Social Security Administration requires for issuance of a SSN.
The required documentation is listed on the SSA website:
A pre-adoptive parent can apply for a temporary tax ID number by submitting form W-7A to the nearest Social Security Administration office.