The N-400 form for naturalization can be downloaded from the U.S. Citizenship and Immigration Services website for free, says USCIS. The USCIS website offers the form in a downloadable PDF, but it also provides resources such as tips as where to file, along with information on filing fees and special instructions.
Other downloadable PDF resources on the website include a document checklist, naturalization eligibility worksheet, naturalization requirements information and electronic notification of the application/petition acceptance form, according to USCIS.
As of January 2015, the fee for filing the N-400 is $595, payable by personal check, cashiers check or money order addressed to the Department of Homeland Security, states USCIS. In applicable cases, an additional $85 biometric fee may exist.