On December 23, 2016 USCIS published updated versions of the forms at uscis.gov/forms. USCIS will accept prior versions of forms, with the exception of Form N-400, until February 21, 2017. However, all filings postmarked 12/23/16 or later must include the new fees or we will reject them. We will accept only the 12/23/16 edition of Form N-400, Application for Naturalization.
Source: USCIS News Alert, 12/29/2016