This bill proposes to amend the Internal Revenue Code of 1986, specifically Section 24(e), to establish a new requirement for claiming the Child Tax Credit (CTC). Under the proposed changes, a taxpayer would not be allowed to claim the CTC for any qualifying child unless both the taxpayer (and both spouses in the case of a joint return) and the child include a valid Social Security Number (SSN) on their tax return. The bill defines a valid SSN as one issued by the Social Security Administration to a citizen of the United States or certain legal residents, and it must be issued before the due date of the tax return. An exception is provided for members of the Armed Forces, where only one spouse on a joint return would need an SSN. Furthermore, the omission of a required SSN would be treated as a mathematical or clerical error, and these amendments would take effect for taxable years beginning after the date of enactment.