You can file Form N-400 up to 90 days before you complete the required period of continuous residence as a permanent resident, which is 5 years on the general route or 3 years if you have been living in marital union with a U.S. citizen spouse (8 CFR 334.2(b), 8 U.S.C. 1427(a), 8 U.S.C. 1430(a)), and by then you must also have been physically present in the United States for at least 913 days, or 548 days on the 3-year route (USCIS Policy Manual, Vol. 12, Part D, Ch. 4, Part G, Ch. 3).
Each of those numbers is counted from a different date, and long trips abroad move them. This guide explains how USCIS counts the dates, what the law, the regulations and the USCIS Policy Manual say about absences, and where the texts do not agree. It covers the time requirements only: it does not say whether an application would be approved. To get your own dates from your green card and your trips, use the calculator.
👉 Find your earliest N-400 filing date
The two routes, side by side
| Route | Permanent residence required | Physical presence required | Early filing opens | Residence in the state or district |
|---|---|---|---|---|
| General (INA §316) | 5 years of continuous residence after becoming a permanent resident (8 U.S.C. 1427(a)) | At least 30 months, which USCIS counts as 913 days, in the 5 years before filing (8 CFR 316.2(a)(4), Policy Manual D.4) | 90 days before the 5-year anniversary of your green card date (8 CFR 334.2(b), Policy Manual D.6) | At least 3 months; if you file early, counted before the interview (8 CFR 316.2(a)(5)) |
| Spouse of a U.S. citizen (INA §319(a)) | 3 years of continuous residence after becoming a permanent resident, living in marital union with a spouse who has been a U.S. citizen for the whole period (8 U.S.C. 1430(a)) | At least 18 months, which USCIS counts as 548 days, in the 3 years before filing (8 CFR 319.1(a)(4), Policy Manual G.3) | 90 days before the 3-year anniversary of your green card date (8 CFR 334.2(b)) | At least 3 months; if you file early, counted before the interview (8 CFR 319.1(a)(5)) |
On both routes, "No person shall file a valid application for naturalization unless he shall have attained the age of eighteen years" (8 U.S.C. 1445(b)). And residence does not stop at filing: the applicant must have "resided continuously within the United States from the date of the application up to the time of admission to citizenship" (8 U.S.C. 1427(a)(2)).
How USCIS counts the 90 days
The regulation says an application "may be filed up to 90 days prior to the completion of the required period of residence" (8 CFR 334.2(b)). The Policy Manual gives the method and an example: "USCIS calculates the early filing period by counting back 90 days from the day before the alien would have first satisfied the continuous residence requirement for naturalization. For example, if the alien would satisfy the five-year continuous residence requirement for the first time on June 10, 2010 USCIS will begin to calculate the 90-day early filing period from June 9, 2010. In such a case, the earliest that the alien is allowed to file would be March 12, 2010 (90 calendar days earlier)." (Policy Manual D.6(D)).
Counted out, March 12 is exactly 90 calendar days before June 10, the anniversary itself: the day before the anniversary is day 1 of the count. In practice, the earliest filing date is your 5-year (or 3-year) anniversary minus 90 calendar days.
The law words it differently: "the application for naturalization may be filed up to 3 months before the date the applicant would first otherwise meet such continuous residence requirement" (8 U.S.C. 1445(a)). Three calendar months are 89 to 92 days depending on the months crossed; USCIS applies 90 days. Filing early does not shorten the residence itself: "the alien is not eligible for naturalization until he or she has reached the required five-year period of continuous residence as a lawful permanent resident (LPR)" (Policy Manual D.6(D)).
Physical presence: 913 or 548 days, and the travel days
The law asks for physical presence "for periods totaling at least half of that time" in the 5 (or 3) years "immediately preceding the date of filing" (8 U.S.C. 1427(a), 1430(a)). USCIS turns that into days: "at least 30 months (at least 913 days) before filing the application" on the general route (Policy Manual D.4(A)), and "at least 18 months (548 days) out of the 3 years immediately preceding the date of filing the application" for spouses (Policy Manual G.3).
Travel days count in your favor: "USCIS will count the day that an applicant departs from the United States and the day he or she returns as days of physical presence within the United States for naturalization purposes" (Policy Manual D.4(A)). Only the whole days in between are days abroad. A trip from July 1 to July 10, 2025 is 8 days abroad, not 10.
Absences: thresholds and effects
Physical presence is a count of days. Continuous residence is a separate test, and a single long trip can break it even when you have enough days. The sources set these thresholds for one continuous absence during the residence period:
| One continuous absence | The law (8 U.S.C. 1427(b)) | The regulation and USCIS |
|---|---|---|
| 6 months (180 days) or less | Not addressed | No threshold for a single absence of this length; multiple short absences can still be reviewed (see below) |
| More than 6 months but less than 1 year (more than 180 days, less than 365) | "shall break the continuity of such residence, unless the applicant shall establish to the satisfaction of the Attorney General that he did not in fact abandon his residence in the United States during such period" | "is presumed to break the continuity of such residence" (Policy Manual D.3(C)(1)); "unless the applicant can establish otherwise to the satisfaction of the Service" (8 CFR 316.5(c)(1)(i)) |
| 1 year or more (365 days or more) | "shall break the continuity of such residence", with an exception for some employment abroad approved in advance | "will automatically break the continuity of residence" (Policy Manual D.3(C)(2)); you can file again "four years and one day" after your return on the 5-year route, or "two years and one day" on the 3-year route (8 CFR 316.5(c)(1)(ii)); what is left of the absence in the new period can still be more than 6 months, a presumption to rebut (Policy Manual D.3(C)(2)) |
To rebut the presumption, the evidence the regulation lists "include, but are not limited to": "(A) The applicant did not terminate his or her employment in the United States; (B) The applicant's immediate family remained in the United States; (C) The applicant retained full access to his or her United States abode; or (D) The applicant did not obtain employment while abroad." (8 CFR 316.5(c)(1)(i)).
Several shorter trips have no threshold in the texts, but they are not ignored: "An officer may also review whether an applicant with multiple absences of less than 6 months each will be able to satisfy the continuous residence requirement." (Policy Manual D.3(C)).
Only the part of an absence inside the period counts. The period is the 5 (or 3) years before the filing date, so it slides forward as the filing date moves, and an old absence shrinks out of it. The Policy Manual's example: an applicant left on January 1, 2010 and returned on January 2, 2011, "exactly 1 year (365 days)". That applicant "must wait until at least January 3, 2015", when the 5-year period "will date back to January 3, 2010": what is left of the absence is under a year but over 180 days, a presumption to rebut. Otherwise, the date is "at least July 6, 2015", because "the applicant was only absent … between July 6, 2010 and January 2, 2011, a period that is not more than 6 months." (Policy Manual D.3(C)(2)). The calculator gives the same two dates for that trip.
If your employer is sending you abroad for a year or more, the exception goes through Form N-470, which "must be filed before the applicant has been absent from the United States for a continuous period of one year" (8 CFR 316.5(d)(1)(i), Form N-470). Afterwards is too late.
Three examples, worked out by the calculator
1. Spouse of a U.S. citizen, no trips. Married to a U.S. citizen since 2020, green card dated May 20, 2024. The 3 years are complete on May 20, 2027, so the N-400 can be filed from February 19, 2027. The 3 years before that date start on February 19, 2024, three months before the green card: counted over the whole period, presence is 1,096 days; counted only from the green card date, 1,005. Both are above 548. On this route the marital union must cover the 3 years immediately before filing, here from February 19, 2024 to February 19, 2027: a marriage from 2020 does.