As of May 5, 2014, the U.S. Citizenship and Immigration Services (USCIS) will ONLY ACCEPT the most recent version of Form N-400, Application for Naturalization (edition date 9/13/2013). All previous versions of Form N-400 will be rejected and returned if received after Sunday, May 4, 2014. Remember that you can find the edition date at the bottom of the form. The most recent version of Form N-400 consists of 21 pages.
For more information about becoming a Naturalization U.S. citizen, please review the USCIS web page, “A Guide to Naturalization“.
Source of Information:
USCIS.gov, 4/29/14, News Alert:
USCIS Will Accept Only the Current Version of Form N-400 Beginning May 5