Direct from the USCIS Bulletin:
"Previous Editions of Forms Accepted Until Feb. 21, 2017, but Must Include New Fees
When new fees for most USCIS forms went into effect on December 23, 2016, we published updated versions of the forms at uscis.gov/forms. We strongly encourage customers to submit these new versions, which are updated with the new fees and have an edition date of 12/23/16.
We 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.
The updated forms are currently available only at uscis.gov/forms, where all of our forms can be downloaded for free. We will issue another alert when paper copies become available through our forms request line (800-870-3676) and forms by mail service.
Remember, the wrong help can hurt! To get information on protecting against immigration services scams, visit uscis.gov/avoidscams.