Make sure you're using the Revised I-9.

Employers must complete a Form I-9 for all newly hired employees to verify their identity and authorization to work in the United States.
Revisions have amended regulations governing the types of acceptable identity and employment authorization documents employees may present to their employers
for completion of the Form I-9. Employers are no longer able to accept expired documents to verify employment authorization on the Form I-9.

Go to the Updated I-9 Handbook for Employers