US Citizenship Residency Requirements: N-400 Rules Explained

You've held a green card for a few years, and citizenship is finally in sight. Then you read about "continuous residence", "physical presence" and "the statutory period", and it all starts to blur. Most N-400 problems start right here, with dates that don't add up.

This guide is a deep dive into the requirements green card holders must meet before applying for naturalization, with a focus on the residence rules. It reflects USCIS guidance as of September 2026. If you're not yet a permanent resident, start with our overview of how to get American citizenship as a foreigner.

The requirements in one table

Special rules also exist for members of the US armed forces, spouses of US citizens working abroad for certain employers, and some other groups. Check USCIS's citizenship pages if one of these might fit you.

Continuous residence: the rule that trips people up

Continuous residence means you've kept the US as your home throughout the required period. It isn't broken by ordinary holidays. It can be broken by long absences.

The USCIS Policy Manual sets out two thresholds:

• More than six months but less than a year: USCIS presumes you broke continuous residence. You can rebut that presumption.
• One year or more: continuous residence is broken, full stop, unless you had an approved Form N-470 for qualifying work abroad before you left.

To rebut the presumption, USCIS looks for evidence that you kept your life in the US during the trip. Helpful evidence includes:

• keeping your US job, or not taking a job abroad
• your spouse and children staying in the US
• keeping your home, lease or mortgage
• filing US tax returns as a resident

A worked example

Say a nurse from Kumasi became a permanent resident on 1 March 2021. In 2023 she spent eight months in Ghana caring for her mother, while her husband and children stayed in their Houston apartment and her hospital held her job open.

The trip is over six months, so USCIS presumes a break. But she has strong rebuttal evidence: her employer's letter, her lease, her children's school records and her resident tax returns. She could apply on the five-year timeline and explain the trip, ideally after an attorney has reviewed her evidence. If she had stayed abroad for 13 months, she would need to start a new residence period.

Physical presence: count the days

Physical presence is simpler but unforgiving. You must have spent at least half the statutory period physically inside the US: 30 months on the five-year route, 18 months on the three-year route.

Count every day abroad, including short trips. Many long-term residents are surprised to find that frequent business travel or long summers overseas push them under the line.

Use your passport stamps, airline records and, if needed, a request for your travel history from US Customs and Border Protection. The N-400 asks you to list every trip of more than 24 hours, so you'll need the list anyway.

The three-month state or district rule

You must have lived for at least three months in the state or USCIS district where you file. If you've just moved from New York to Texas, wait until you've been in Texas for three months, or use the right office for where you lived before. Students may be able to apply from where they study or where their family lives, depending on their circumstances.

Filing early: the 90-day window

USCIS lets you file Form N-400 up to 90 days before you complete your three or five years of permanent residence. It has an early filing calculator on its website.

The early window applies only to the time-as-a-resident requirement. You must already meet physical presence, the three-month state rule and everything else on the day you file. Filing even one day before the window opens can lead to a denial and a lost fee.

Good moral character and the 2026 changes

You must show good moral character for the statutory period and until you take the oath. Serious crimes, false claims to US citizenship, failing to pay court-ordered child support, and lying to immigration officers are examples of conduct that can bar you.

On 25 August 2026, USCIS issued policy alert PA-2026-10, which reintroduces personal investigations, often called neighborhood investigations, under section 335(a) of the Immigration and Nationality Act. USCIS says it's ending the general waiver of these investigations that had been in place for decades. Expect officers to look more closely at your community ties and history, and be ready to back up what you say.

The English and civics tests

The English test has three parts. The officer judges your speaking during the interview. You must read aloud one of three sentences correctly and write one of three sentences correctly.

Which civics test you take depends on when you filed:

If you're 65 or older and have been a permanent resident for at least 20 years, USCIS gives you a test of 10 questions from a special bank of 20, and you can take it in your preferred language. Other age-and-residence exemptions from the English test exist, and applicants with qualifying disabilities can request an exception with Form N-648.

If you fail any part, USCIS retests you on that part, usually 60 to 90 days after your first interview.

N-400 fees and money matters

These figures come from the USCIS fee schedule dated 9 September 2026. If you want a reduced fee or waiver, you must file on paper with supporting documents.

Beyond the form, budget for legal advice if your case isn't straightforward, court records, translations, time off work for your biometrics appointment and interview, and your first US passport. Once you naturalize, you're taxed as a US citizen on your worldwide income, even if you later move abroad, so plan your finances with that in mind.

The N-400 process, step by step

1. Confirm your dates. Find the "resident since" date on your green card and count forward.
2. List every trip abroad with exact dates, and total your days outside the US.
3. Check the three-month state rule for where you'll file.
4. Gather documents, including your green card, marriage and spouse's citizenship evidence for the three-year route, tax transcripts and any court records.
5. File Form N-400 online or on paper, and keep your receipt notice. It extends your green card for two years.
6. Attend biometrics if scheduled, and cooperate with any investigation.
7. Attend your interview, answer questions under oath and take the English and civics tests.
8. Take the Oath of Allegiance. You become a citizen only at the oath ceremony.

Scams and costly mistakes

• Unlicensed "immigration consultants" and notarios. Use a licensed attorney or a Department of Justice accredited representative.
• Anyone who offers to "fix" your travel dates. Your trips are recorded, and false answers can lead to denial and worse.
• Study apps using the old 100-question list when you need the 2025 test.
• Paying a third party to "speed up" your case. No one can buy priority with USCIS.

Your checklist

• Confirm you're at least 18 and know your exact permanent residence start date.
• Total your days outside the US and check the 30-month or 18-month minimum.
• Flag any trip over six months and gather rebuttal evidence.
• Make sure you've lived three months in your current state or district.
• Review your tax filings and any arrests or court cases with a professional.
• Download the official 2025 civics questions and practise aloud.
• Decide whether you qualify for the reduced fee before choosing how to file.

Residence rules reward people who keep good records. Build your travel log now, and your N-400 will be far easier when your date arrives. For family members still abroad, our overview of ways to migrate to the USA explains the routes a new citizen can use to sponsor them.