Fillable N-400 Application for Naturalization

The N-400, Application for Naturalization is the official USCIS form used by lawful permanent residents to become U.S. citizens. Our fillable PDF version lets you complete the entire application directly in your browser—no extra software required.

What Is the N-400 Form?

The N-400 collects personal information, residency history, employment, travel, and moral character details. It also includes sections for English and civics test exemptions, medical certifications, and supporting documents.

How to Fill Out the N-400 Online

Simply click the “Fill out this form” button below. The Formize PDF Filler loads instantly, allowing you to type, select, and navigate each field just like a web form. All changes are saved automatically.

Common Mistakes to Avoid

• Using lowercase letters or fancy fonts – USCIS requires capital letters.
• Leaving any required field blank – the filler highlights missing information.
• Submitting outdated edition dates – make sure the PDF shows the current edition (01/20/25).
• Uploading non‑English documents without certified translations.

Eligibility & Filing Requirements

Before you start, confirm you meet one of the standard eligibility paths: 5 years of continuous residence, 3 years if married to a U.S. citizen, or qualifying military service. Gather your Green Card, marriage certificates, tax records, and any supporting evidence.

Download the Official PDF

For reference or offline completion, you can download the official USCIS version of the N-400 form. Our fillable version mirrors the exact layout, so you can print it later if you prefer mailing your application.

Official USCIS N-400 PDF (download)