Find the SSA office nearest you by logging on to the SSA's Office Locator at http://www.socialsecurity.gov/locator. If you'd prefer, you can send in a completed Form SS-5 along with your identification documents to your local SSA office by mail. Most people apply in person, however, because you'll need to provide the SSA with originals or certified copies of all identification documents.

Once you've submitted your application, you should receive a Social Security card in six to 12 weeks. It may take substantially longer to process your application if your child is one year of age or older, because the SSA will contact your state's department of vital statistics to confirm that the birth certificate you have provided is valid.

If You Are Adopting a Child

If the child you are adopting is a United States citizen, your child probably has a Social Security number already. But if you are adopting domestically and your child does not have one, you can obtain an Adoption Taxpayer Identification Number (ATIN) to claim child-related tax breaks while your child's adoption is pending. To apply for one, complete IRS Form W-7A, Application for Taxpayer Identification Number for Pending U.S. Adoptions. The ATIN will be valid for only two years, at which point you can extend it if your child's adoption is still not final. Once the adoption is final, you must stop using the ATIN and get a Social Security number for your child following the process described above.

If you are adopting a child from another country, you will have to wait until the adoption is final and your child has entered the United States before you can obtain a Social Security number for your child. Once that happens, you can use the process described above.