Employers are required to fill out an I-9 form for each new employee.   This is to establish that the new employee is allowed to work here in the U.S.   The most recent form is dated 3/8/2013.   Employers may continue to use that form until January 21, 2017.   They can, of course, use the new form, dated 11/14/2016, and starting January 22, 2017, employers must use the new form.