On July 17, 2017, U.S. Citizenship and Immigration Services issued a new Form I-9. Employers can use the new form, or the form issued as of November 14, 2016, until September 17, 2017, thereafter, the new form must be used. The new form does not contain significant material changes, although it does revise List C of acceptable documents to include birth certificates issued by the State Department. For practical purposes, employers should begin using the new form as soon as possible (rather than risk using the old form and risk forgetting to switch on September 17th.
The revised Form I-9 can be found here: https://www.uscis.gov/i-9