I have worked in human resources for several months, and I recently attended I-9 training. The trainer said that I should accept a Social Security card for I-9 purposes even if it has not been signed. I have always been told that a person had to sign a Social Security card before it became valid. Can I accept an unsigned card for the I-9?



Yes. The Court of Appeals for the Eighth Circuit issued an opinion in 2006 indicating that even an unsigned Social Security card serves as proof of employment authorization. (The case is U.S. v. Pool-Chan, 453 F.3d 1092 (8th Cir. 2006).) U.S. Citizenship and Immigration Services (USCIS) and the U.S. Department of Justice (DOJ) have each provided guidance to employers that reiterates the court’s decision, stating that employers must not reject unsigned Social Security cards during the I-9 process.
For the DOJ’s guidance, see this opinion letter. And here is the confirmation from USCIS.