N-400 eligibility calculator
Know the day you can file for citizenship.
Enter your green card date and your trips abroad. N400Tracker works out your physical presence, flags trips that put continuous residence at risk, and shows your earliest N-400 filing date.
Free to download. Optional one-time Premium unlock, no subscription.
What USCIS checks
Four requirements. One screen.
5 or 3
Years as a resident
5 years, or 3 if married to a U.S. citizen. You can file up to 90 days early.
30 / 18
Months physically present
Half of the period must be spent inside the United States. Every trip counts.
180
Days abroad
A single trip of more than 6 months can break continuous residence. The app warns you first.
3
Months in your state
You must live in the state or USCIS district where you file for at least 3 months.
Features
Built for the whole path to the oath.
Travel log
Every trip, counted correctly
Log trips with one tap when you leave and when you return. Totals for days abroad and your longest trip update instantly, and long trips are flagged before they become a problem.
Trip planner
Check a trip before you book it
Pick a departure date and length. The planner tells you the date you need to be back and how much margin you have, so a vacation does not reset your clock.
Civics test
Practice the test you will actually take
Official USCIS questions for both the 2025 test (filed on or after October 20, 2025) and the 2008 test. Exam mode follows the real stopping rules; study mode lets you browse the full catalog.
Interview prep
A document checklist for interview day
Green card, passports, travel records, tax returns and more, ticked off as you gather them.
Guides
The N-400 rules, in plain English.
- When can I apply for citizenship? N-400 eligibility explainedWork out the earliest date you can file Form N-400: the 5-year and 3-year tracks, the 90-day early filing window, physical presence and continuous residence.
- 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.
Pricing
Free to use. Pay once if you want more.
Free
$0
- Eligibility and physical presence calculator
- Trip entry and trip planner
- Unlimited practice exams
- Full official civics catalog in study mode
Premium Lifetime
$4.99 one time
- Everything in Free
- Permanent trip history that survives closing the app
- Saved practice exam history
- Resume an unfinished exam
Not a subscription. Bought inside the app through your App Store or Google Play account and restorable on your other devices.
Privacy
Your immigration history never leaves your phone.
No account. No server. No analytics or ads. The app works offline, and if you delete it, your data is gone because we never had it.
FAQ
Questions
When can I file Form N-400?
Most permanent residents can file 90 days before reaching 5 years as a resident, or 3 years if married to and living with a U.S. citizen. You also need enough physical presence, unbroken continuous residence and at least 3 months in your state or USCIS district. N400Tracker calculates these from your green card date and your trips.
Is N400Tracker a subscription?
No. The app is free. Premium is a one-time purchase of US$4.99 with no renewal and nothing to cancel.
Where is my data stored?
Only on your phone. There is no account, no server and no analytics. Deleting the app deletes your data.
Which languages does the app support?
English, Spanish, Portuguese and Turkish.
Is there an Android version?
Yes, it is coming to Google Play soon with the same features and the same one-time Premium unlock.
Is this legal advice?
No. N400Tracker is an informational tool and is not affiliated with USCIS. Confirm your eligibility with USCIS or a licensed immigration attorney.
Stop counting days on a spreadsheet.
Free to download. Optional one-time Premium unlock, no subscription.