Guide
When can I apply for citizenship? N-400 eligibility explained
Most green card holders can file Form N-400 90 days before reaching 5 years as a permanent resident, or 3 years if married to a U.S. citizen. The date only works if your time in the U.S. and your trips abroad also meet the rules.
The short answer
- 5 years as a permanent resident, or 3 years on the marriage track.
- You can file up to 90 days before you reach that point.
- Physical presence: at least 30 months in the U.S. (18 months on the 3-year track).
- Continuous residence: no trip long enough to break it.
- 3 months living in the state or USCIS district where you file.
Step 1: pick your track
There are two common paths to naturalization for permanent residents.
The 5-year track is the general rule. You need 5 years as a lawful permanent resident (LPR). It applies to most people, including people who are married to a citizen but do not meet the marriage track conditions.
The 3-year marriage track is shorter. You need 3 years as a permanent resident, and during those 3 years you must be married to and living in marital union with a U.S. citizen. Your spouse must have been a citizen for the whole 3 years. If your spouse naturalized recently, or you have not lived together for the full period, the 5-year track may be the one that applies.
Your starting point on both tracks is the date you became a permanent resident. It appears on your green card as "Resident Since".
Step 2: apply the 90-day early filing window
USCIS accepts Form N-400 up to 90 days before you first meet the 5-year (or 3-year) continuous residence period. So your earliest filing date is your 5-year or 3-year anniversary minus 90 days.
This is a firm line. An application filed even one day too early is denied, and the fee is not refunded. Count days, not months. Our 90-day early filing guide explains how to count and why "3 months" can give the wrong date.
A worked example
Maria's green card says she has been a resident since March 15, 2021. She is on the 5-year track.
| Step | Date |
|---|---|
| Resident since | March 15, 2021 |
| Reaches 5 years | March 15, 2026 |
| Minus 90 days: earliest filing date | December 15, 2025 |
Maria can file on or after December 15, 2025, as long as she also meets the rules below. If she files on December 14, 2025, she is one day too early.
Now take David, who became a permanent resident on March 15, 2023 and has been married to and living with a U.S. citizen spouse (a citizen the whole time) since before that date. On the 3-year track he reaches 3 years on March 15, 2026, so his earliest filing date is also December 15, 2025.
Step 3: check physical presence
Being a resident on paper is not enough. You must have been physically inside the U.S. for at least 30 months during the 5-year period, or 18 months during the 3-year period. Every day you spend abroad reduces that total, even on short vacations.
If you travel often, add up your trips before you file. The physical presence guide shows how.
Step 4: check continuous residence
Continuous residence is about long trips. An absence of more than 6 months but less than 1 year creates a presumption that your continuous residence was broken, which you can try to rebut with evidence. An absence of 1 year or more breaks it, with a narrow exception for people with an approved Form N-470.
A broken period can move your eligibility date later. Read the continuous residence guide if you have any trip longer than about 6 months.
Step 5: 3 months in your state or district
Before you file, you must have lived for at least 3 months in the state or USCIS district where you apply. If you moved recently, this can be the last date to clear. Students may file where they go to school or, if they depend on their parents, where their parents live.
The other requirements
Timing is only part of eligibility. You also need to:
- Be at least 18 years old when you file.
- Show good moral character.
- Pass the English test (reading, writing and speaking).
- Pass the civics test. See which civics test applies to you.
- Show attachment to the principles of the U.S. Constitution.
USCIS lists the full requirements at uscis.gov/citizenship. When your date is close, the N-400 document checklist helps you prepare.
Let the dates add up for you
Doing this by hand is fine for one trip. With many trips it gets easy to miscount. N400Tracker takes your green card date and your trips, then shows your earliest filing date, your physical presence days and any trip that puts continuous residence at risk, for both the 5-year and 3-year tracks.
Common questions
When can I apply for U.S. citizenship with a green card?
Most permanent residents can file Form N-400 up to 90 days before reaching 5 years as a permanent resident. If you are married to and living with a U.S. citizen who has been a citizen for the whole time, the period is 3 years instead. You must also meet physical presence, continuous residence and the 3-month state or district residence rule.
Which date do I count from?
Count from the date you became a permanent resident. It is printed on your green card as the resident since date.
Do trips abroad change my filing date?
They can. Short trips count against physical presence. A trip of more than 6 months can break continuous residence, and a trip of 1 year or more generally breaks it, which can push your eligibility later.
Can I apply before the 90-day window opens?
No. USCIS denies an N-400 filed even one day too early, and the filing fee is not refunded.
This guide is informational only and is not legal advice. N400Tracker is not affiliated with USCIS. Confirm your eligibility with USCIS or a licensed immigration attorney before you file. Official source: USCIS continuous residence and physical presence requirements.
More guides
- The N-400 90-day early filing rule: how to count itHow the N-400 90-day early filing rule works, how to count the days correctly, why 3 months is not 90 days, and why filing one day early leads to denial.
- Continuous residence for naturalization: trips over 6 monthsHow trips abroad affect continuous residence for the N-400: under 6 months, 6 months to 1 year, 1 year or more, Form N-470, and how to plan a safe return date.
- The physical presence requirement for citizenshipHow the N-400 physical presence rule works: 30 of 60 months (18 of 36 for marriage), how to count days outside the U.S., a worked example and records to keep.
- 2025 civics test vs 2008: which one do you take?Your N-400 filing date decides your civics test. Compare the 2025 and 2008 tests: question bank, questions asked, passing score, stop rule and how to study.
- N-400 interview documents checklistWhat to bring to your N-400 citizenship interview: identity and travel documents, tax records, marriage track proof, special situations and a day-before list.