The official source for Form N-400 is USCIS.gov—specifically, the forms section at uscis.gov/n-400. That's the only place you should download or access the form. Third-party sites that offer immigration forms are often outdated, may charge for forms that are free from USCIS, and sometimes provide incorrect versions that will cause your application to be rejected. Go directly to the USCIS website every time.
USCIS updates form versions periodically. The edition date appears in the lower left corner of each page of the form. USCIS will only accept the current edition—submitting an outdated version results in rejection. Before you print or fill out any version of N-400, verify it matches the edition date on the USCIS forms page.
You have two options for accessing and completing the N-400: online through your USCIS online account, or by downloading and printing the paper version.
Online filing (myUSCIS account): USCIS strongly encourages online filing. You create a free account at myaccount.uscis.gov, select Form N-400, and complete it through the online interface. The online form walks you through each section with built-in instructions and validation—it'll flag common errors before you submit. You can save your progress and return to it. After submitting, you get immediate confirmation and can track your case status online. Online filing is faster to submit and generally faster to process.
Paper filing: Download the PDF from uscis.gov/n-400, print it, and fill it out by hand or using PDF form fields. Mail the completed form with supporting documents and the filing fee to the appropriate USCIS lockbox address. Paper filing takes longer to process and doesn't allow real-time case tracking. The lockbox address depends on where you live—USCIS publishes the current mailing address by location on the N-400 form instructions page.
Most applicants are better served by online filing unless they have a specific reason to file by paper (certain fee waiver situations, for example, may be handled differently).
The filing fee for most N-400 applicants is $760 as of 2024, plus an $85 biometrics fee. Total: $845 for most applicants. Fee amounts are set by USCIS and subject to change—always verify the current fee on the USCIS website before submitting payment.
For online filing, payment is made by credit card, debit card, or bank account (ACH) through the USCIS online payment system. For paper filing, payment is made by check, money order, or credit card using Form G-1450. Make checks payable to the U.S. Department of Homeland Security.
Fee waivers are available for applicants who demonstrate financial hardship. File Form I-912 (Request for Fee Waiver) with your N-400 if you're requesting a waiver. Fee exemptions (not waivers) are available for certain categories including active duty military members. Review the N-400 instructions to confirm if any exemption applies to you before paying.
The N-400 form alone isn't sufficient—you need to include supporting documents. Required documents vary based on your specific eligibility category, but the standard list for most applicants includes:
A copy of your permanent resident card (green card), both front and back. Two passport-style photographs (required for paper filings; online filers typically don't submit physical photos at this stage). If you're applying under the three-year spouse-of-citizen rule: a copy of your U.S. citizen spouse's passport or naturalization certificate, and a copy of your marriage certificate. If your name has changed from what's on your green card: legal documentation of the name change (court order or marriage certificate).
For applicants with certain conditions or histories, additional documents may be required: certified court disposition records for any arrests or charges, tax returns if USCIS requests evidence of financial responsibility, military records for veterans, and documentation supporting any disability exception claims.
Don't submit original documents unless USCIS specifically requests them. Submit legible copies. If documents are in a language other than English, you must include a certified English translation. USCIS has specific certification requirements for translations—the translator must certify that the translation is accurate and that they're competent to translate.
The N-400 has multiple parts, each covering a different aspect of your history and eligibility. Taking your time and being accurate matters more than speed.
Part 1 — Your eligibility category: Select the category under which you're applying. Most applicants are either the five-year rule or the three-year spouse-of-citizen rule. Select the correct one—if you select the wrong basis, your application will have problems.
Parts 2-4 — Personal information, address, and work history: Complete these sections accurately. For addresses and employment, go back exactly as far as the form requires (five years for most applicants). Include every address and every employer, even if you moved frequently or changed jobs often. Gaps raise questions.
Part 5 — Time outside the United States: List every trip outside the U.S. of 24 hours or longer during the required period. Include destination country, departure date, return date, and purpose of trip. Be precise about dates—USCIS verifies travel history against CBP entry/exit records. Discrepancies between your reported trips and CBP records will be flagged at your interview.
Part 6 — Marital history: List your current spouse and all previous spouses. For each, include dates of marriage and, if applicable, how the marriage ended and when. If you're applying under the three-year spouse rule, provide detailed information about your current marriage.
Part 12 — Good moral character: This section has numerous yes/no questions about criminal history, immigration violations, financial obligations, and other factors that affect good moral character. Answer every question honestly. Read each question carefully—some are worded precisely in ways that matter. "Have you EVER" means your entire life, not just the last five years. For arrests that resulted in no conviction: still disclose and explain. For expunged records: the N-400 instructions specify whether expunged records must be disclosed—follow those instructions exactly.
Once USCIS receives your application, you'll receive a receipt notice (Form I-797) confirming acceptance. For online filers, this appears in your online account and is also mailed. Keep this notice—it contains your receipt number, which you'll use to track your case.
Shortly after your receipt notice, USCIS will mail you a biometrics appointment notice. The biometrics appointment is at an Application Support Center (ASC) near you. You'll have your fingerprints, photo, and signature collected for the background check. Bring your appointment notice and a valid photo ID. Biometrics appointments typically last about 20 minutes and can't be rescheduled without good cause.
After biometrics, your application enters the adjudication queue. The wait for an interview varies significantly by USCIS field office. Check current processing times on the USCIS website under Tools > Processing Times. If your case is significantly outside the posted processing time for your office, you can request an inquiry through your USCIS account or contact the USCIS Contact Center at 1-800-375-5283.
Your naturalization interview will be scheduled at the USCIS field office with jurisdiction over your address. Attend on time with all required documents. If you need to reschedule, do so through your online account or by calling USCIS before the scheduled date—missing a biometrics or interview appointment without rescheduling can result in abandonment of your application.
A few patterns cause problems consistently:
Using an outdated form version—always download directly from USCIS.gov immediately before filing, not from a file you saved months ago. Sending the form to the wrong address—USCIS has multiple lockbox addresses, and the correct one depends on your state. Check the current mailing instructions on the USCIS forms page. Forgetting to sign the form—unsigned N-400 applications are rejected. Online filers sign electronically; paper filers must physically sign in the designated space. Failing to include all required documents—missing your green card copy or marriage certificate (for three-year applicants) causes delays. Answering good moral character questions without reading them carefully—these questions have specific scopes and wording that matters legally.
Your Certificate of Naturalization, received at your oath ceremony, is proof of your U.S. citizenship. It's an important document—store it securely. You can use it (along with a valid government ID) to apply for a U.S. passport, update your Social Security record, register to vote, and access other rights and benefits of citizenship.
Apply for a U.S. passport soon after naturalization if you travel internationally. The passport is the most convenient and universally accepted proof of U.S. citizenship. Apply at a passport acceptance facility with your Certificate of Naturalization, a passport photo, and the application fee.
Update your voter registration. As a citizen, you can vote in federal, state, and local elections. Registration deadlines vary by state—register well before the next election cycle to ensure eligibility.
The N-400 rewards careful, thorough applicants and punishes rushed ones. Take the time to gather all your documents before you start filling out the form. Make sure your travel history is complete and accurate—go through your passport pages, bank records, or any other records that help you reconstruct exact dates. Read every question in Part 12 carefully and answer honestly.
If you're unsure about anything on the form, the USCIS website has detailed form instructions, and USCIS has a contact center that answers questions. For complex situations, an immigration attorney or accredited representative can review your application before you submit it—worth the cost if it catches a problem that could delay or jeopardize your application.
The N-400 is the final step in a long journey toward U.S. citizenship. File it well, prepare for your interview, and approach the process with the seriousness it deserves. The citizenship you'll earn is permanent and comes with rights and responsibilities that will shape the rest of your life in the United States.