Prepare N-400 – Application for Naturalization

Who this page is for

This page is for lawful permanent residents who want a structured way to prepare the information needed for Form N-400, Application for Naturalization. It is intended for people who are gathering details about their residence, travel history, family, and background so they can copy those details into the official USCIS form or an online application. The guide is also useful for anyone who wants to review the main topics covered on Form N-400 in a browser-friendly layout before signing and submitting an application to USCIS.

What is Form N-400?

Form N-400, Application for Naturalization, is a U.S. Citizenship and Immigration Services (USCIS) form used by eligible lawful permanent residents who wish to apply for U.S. citizenship. The application asks about identity, immigration history, travel, family, employment, tax compliance, and other background factors so USCIS can determine whether the applicant meets the requirements for naturalization. Filing Form N-400 is generally required for most people who want to become U.S. citizens through this process.

Used by lawful permanent residents (green card holders) to apply for U.S. citizenship through the naturalization process.

USCIS uses the information on Form N-400 to evaluate whether you satisfy eligibility criteria such as continuous residence, physical presence, good moral character, knowledge of English and U.S. civics (unless exempt or accommodated), and attachment to the principles of the U.S. Constitution. The form also helps USCIS decide whether any issues in your background need closer review. The application is typically followed by biometrics and an interview, and if approved, an Oath of Allegiance ceremony.

On this page you prepare for the official USCIS Form N-400 (Edition 09/17/19) by understanding what it covers and where to find the most recent instructions. You can then download the official PDF, review it carefully, sign where required, and follow USCIS directions for filing the application and supporting documents.

Example situations where someone may use Form N-400

Form N-400 is commonly used in a variety of naturalization situations. Examples include:

• A lawful permanent resident who has held a green card for at least five years and meets the continuous residence and physical presence requirements applying to become a U.S. citizen.
• A lawful permanent resident who has been married to and living with a U.S. citizen for a qualifying period and who may be eligible under a three-year naturalization rule, as described by USCIS.
• Certain lawful permanent residents serving in the U.S. armed forces who may qualify for special naturalization provisions related to military service.
• Individuals who qualify for naturalization under specific sections of the Immigration and Nationality Act, such as those with certain types of overseas employment or family histories that interact with naturalization rules.
• Applicants who previously filed other immigration forms, such as adjustment of status applications, and are now ready to apply for citizenship based on time in permanent resident status.

These examples are illustrations of how Form N-400 is often used based on general USCIS guidance. They are not a substitute for legal advice or for the official USCIS instructions that explain who is eligible to file and when an application may be appropriate.

How to fill Form N-400

The official USCIS instructions for Form N-400 explain the exact structure of the form and how each part should be completed. While this page does not display the full application line-by-line, the outline below shows the kinds of sections you typically see on the current edition. You can use this overview to organize your information before you start filling out the official USCIS PDF or an online application through a USCIS account.

1. Information about your eligibility. Form N-400 begins by asking how you qualify for naturalization, such as under the five-year rule, three-year rule, or based on qualifying military service. USCIS uses this information to apply the correct statutory requirements and to decide which parts of the form and which evidence are relevant for your case.
2. Information about you. The application collects detailed biographic information, including your legal name, other names you have used, date and place of birth, country of citizenship or nationality, and U.S. Social Security number if you have one. You also provide your current and prior addresses and other contact information, which helps USCIS understand your residence history.
3. Residence, employment, and travel history. USCIS asks for your employment history, addresses going back a certain number of years, and a record of trips outside the United States to evaluate continuous residence and physical presence. This section may require you to list multiple trips and dates, so collecting travel records in advance can be helpful.
4. Family information. Form N-400 requests information about your marital history, current spouse, former spouses, and children, if any. These questions help USCIS understand your family situation, verify certain eligibility categories, and confirm consistency with prior immigration filings.
5. Background questions. A significant portion of the application is devoted to questions about taxes, selective service registration in some cases, criminal history, prior immigration issues, and other topics related to good moral character and security screening. USCIS uses your answers, along with documents and background checks, to evaluate whether you meet naturalization requirements.
6. Signature, interpreter, and preparer sections. Like many USCIS forms, Form N-400 includes a section where you certify under penalty of perjury that the information you provided is true and correct, followed by your signature and the date. Additional sections are provided if an interpreter or preparer helped you complete the application, and those individuals may also need to sign.

After you review the USCIS instructions and gather your information, download the official Form N-400 or start an online application, fill it out according to the instructions, sign where required, and follow USCIS guidance on how and where to submit your application and pay any applicable fees.

Common mistakes on Form N-400

• Selecting the wrong eligibility category or leaving the basis for naturalization unclear compared to the USCIS instructions.
• Omitting trips outside the United States or providing incomplete travel dates, which can affect USCIS’s evaluation of continuous residence and physical presence.
• Leaving questions about criminal history, taxes, or prior immigration issues blank instead of answering as instructed, leading to Requests for Evidence (RFEs) or delays.
• Not updating name or address information to match current legal records and previous filings, which can cause confusion or additional questions.
• Forgetting to sign and date the application or missing required signatures for interpreters or preparers when those sections apply.
• Using an outdated edition of Form N-400 when USCIS requires use of the current version listed on its website.
• Not including required supporting documents, such as copies of the permanent resident card or marital documentation when needed for your eligibility category.
• Failing to keep a personal copy of the entire application and supporting evidence before submitting it to USCIS.

When Form N-400 is usually not used

Form N-400 is specific to naturalization applications. Other forms are generally used in different situations, for example:

• Lawful permanent residents who are not yet eligible for naturalization or who are still in the process of obtaining or renewing their green card usually use other USCIS forms, such as Form I-485 or Form I-90, instead of Form N-400.
• Individuals seeking temporary visas for work, study, or travel generally use nonimmigrant visa forms and processes rather than a naturalization application.
• People who acquired or derived U.S. citizenship automatically under certain laws may rely on other processes or forms, such as applying for a U.S. passport or using Form N-600 for a certificate of citizenship, depending on their situation.
• Situations involving only permanent residence (for example, initial green card applications) usually involve immigrant visa or adjustment of status forms, not Form N-400, which is focused on citizenship.
• Cases where a person is not a lawful permanent resident and does not qualify under special provisions; in those situations, naturalization through Form N-400 may not yet be available.

These are broad examples based on how USCIS organizes immigration benefits. They do not replace the official USCIS instructions or legal advice about whether Form N-400 is appropriate for your situation.

Where to find the official USCIS instructions for Form N-400

USCIS publishes the official instructions for Form N-400 on its website along with the most current edition of the application. Those instructions explain eligibility categories, required evidence, filing options, fees, testing requirements, and next steps in the naturalization process. You can read them in the official instructions PDF for Form N-400 available from USCIS. This page is only a helper for organizing information and understanding the application and does not replace the official USCIS instructions or guidance from a qualified representative.

Before you sign and file Form N-400, it is a good idea to compare your completed application with the USCIS instructions to confirm that you are using the correct edition, have included all required pages, and understand what additional forms, testing, or steps may be needed in your type of case.

Where to get a blank or replacement Form N-400

If you need a blank application, you can download the current official Form N-400 PDF directly from USCIS. This page points you to that official PDF so you can print and complete it or use it as a reference while reviewing the USCIS instructions. USCIS may also provide online filing options for many N-400 applicants, which are explained in the official naturalization resources.

If you discover an error after preparing or filing an application, USCIS instructions and notices explain how corrections, updates, or withdrawals may be handled. Keeping a copy of your final signed N-400 and supporting documents can make it easier to understand what USCIS has on file and to prepare any future filings or responses.

Glossary of key terms on Form N-400

Naturalization

Naturalization is the process through which a non-U.S. citizen, usually a lawful permanent resident, applies to become a U.S. citizen if certain requirements are met. Form N-400 is the primary USCIS application used for most naturalization cases.

Lawful permanent resident

A lawful permanent resident is a noncitizen who has been granted the right to live and work in the United States indefinitely, often evidenced by a Permanent Resident Card (green card). Many naturalization applicants must show a specific period of lawful permanent residence as part of eligibility for Form N-400.

Continuous residence

Continuous residence refers to maintaining a residence in the United States for a required period without long, disruptive absences. USCIS uses continuous residence rules, along with physical presence rules, to determine whether an applicant for naturalization meets the statutory residency requirements.

Physical presence

Physical presence generally refers to the number of days you have actually been inside the United States during the required period before filing Form N-400. USCIS compares the time you were physically in the country with the minimum required number of days for your eligibility category.

Good moral character

Good moral character is a legal concept in U.S. immigration law that refers to a person’s conduct and history over a specified period, often the years immediately before filing Form N-400. USCIS reviews factors such as criminal history, tax compliance, and other behavior to determine whether an applicant satisfies this requirement for naturalization.

Security best practices when sharing information from Form N-400

Form N-400 contains detailed personal information, including addresses, dates of birth, travel history, and background questions. Because of this, it is sensible to treat the application and any supporting evidence as sensitive documents. The following general practices may be helpful when you handle draft or final versions of your application.

• Store digital copies of your application and evidence in locations you control, such as secure folders or password-protected storage services.
• Avoid sharing your full application or supporting documents by public links or unsecured email when a more private method is available.
• Keep track of which copies you send to any representative or helper so you know who has access to sensitive details about your history and background.
• Confirm that you are using official USCIS addresses, secure lockbox locations, and official USCIS online portals before entering payment information or uploading documents related to your N-400 application.

These are general security considerations. Always follow the specific directions you receive from USCIS, the Department of State where relevant, or any authorized representative assisting with your case.

Common questions people also ask about Form N-400

• Is Form N-400 the same as a green card application? No. Form N-400 is used by eligible lawful permanent residents to apply for U.S. citizenship, while applications for permanent residence typically involve different forms, such as Form I-485 or consular immigrant visa procedures. Naturalization generally comes after someone has already become a permanent resident and met certain additional requirements.
• Do I have to take an English and civics test for Form N-400? Many applicants must demonstrate an ability to read, write, and speak basic English and show knowledge of U.S. history and government through a civics test. However, USCIS provides certain exceptions or accommodations based on age, length of permanent residence, or disability, as explained in the official N-400 instructions and related guidance.
• Do I need a lawyer to file Form N-400? USCIS does not require applicants to work with a lawyer, but some people choose to consult an immigration attorney or accredited representative because naturalization rules and background issues can be complex. This page is only an informational helper and is not a substitute for individualized legal advice.

FAQ about Form N-400

Important disclaimer

This site is not a law firm and is not affiliated with USCIS or any government agency. It provides a private, third-party resource to help you understand and prepare for the official Form N-400, Application for Naturalization. The information on this page is general and does not replace the official USCIS instructions or professional legal advice. Always review your completed application and follow the directions from USCIS, the Department of State where relevant, and any qualified representative assisting with your case.