Employers, agricultural recruiters and referrers for a fee must: (1) verify both the identity and employment authorization of each person hired, regardless of citizenship; (2) properly complete, retain and make available for inspection, Form I-9. The newly hired individual must: (1) attest to being a U.S. citizen or national, a lawful permanent resident, or an alien authorized to work in the U.S.; and (2) present to employer a document or combination of documents designated by statute and regulation as acceptable. The employer must examine the document(s), record the information on the I-9, and attest that they appear to be genuine and to relate to the person presenting the document(s).
On April 15, 2011, USCIS adopted a final rule meant to improve the integrity of the I-9 process. The main changes made by the final rule include: (1) added language prohibiting employers from accepting expired documents; (2) removed outdated documents from the list of acceptable documents; (3) added documents applicable to certain citizens of the Federated States of Micronesia and the Republic of the Marshall Islands.
http://1.usa.gov/FinalRuleI-9
Q&As on Final Rule: http://1.usa.gov/I-9FinalRuleQs