The FEIE's 330 Days, and Why December 31 Is Not the Deadline You Think

To exclude foreign earned income from US tax under the physical presence test, you need 330 full days in a foreign country during any period of 12 consecutive months. That is the IRS's own wording, and the word doing the work is "any." The 12 months do not have to run from January to December.

For 2026, the foreign earned income exclusion is worth up to $132,900 per qualifying person, set in the IRS's annual inflation adjustments (Revenue Procedure 2025-32). Whether you can claim all of it, part of it or none of it this year comes down to dates, and the date most people are watching, December 31, mostly is not one of them.

What follows is how the IRS's guidance reads. It is not tax advice, and I say where you need someone who can give it.

Two tests, two clocks

There are two ways to qualify for the exclusion, and they run on different clocks.

The bona fide residence test does use the tax year. You have to be a bona fide resident of a foreign country "for an uninterrupted period that includes an entire tax year," which for most people means January 1 to December 31. Someone who moved abroad in September 2026 cannot meet it until they have lived there through all of 2027. If you have heard that the exclusion runs on the calendar year, this is the test that does.

The physical presence test does not care about the calendar. The IRS says it "is based only on how long you stay in a foreign country or countries." And it gives four rules for choosing the 12 months:

• The period can begin on any day of the month. It ends the day before the same calendar day, 12 months later.
• It has to be made up of consecutive months.
• You do not have to start it on your first full day abroad or end it on the day you leave. "You can choose the 12-month period that gives you the greatest exclusion."
• Twelve-month periods can overlap one another.

So if you have been counting days since January 1 and wondering whether you will reach 330 by New Year's Eve, you are counting against the wrong test.

A September move, worked through

The dates here are my illustration. The rules are the IRS's.

Say you fly out of the US on August 31 and land on September 1. A day counts only if you spend all of it in a foreign country: the IRS defines a full day as "a period of 24 consecutive hours, beginning and ending at midnight," and time spent over international waters does not count. So your first full day abroad is September 2. The IRS's own example works the same way: leave on June 10, arrive at 9:00 a.m. on June 11, first full day June 12.

Your 12-month window can then run from September 2, 2026 through September 1, 2027: 365 days. If 330 of them have to be full days in a foreign country, 35 are left for everything else, meaning trips back to the US plus the travel days on either side, since the day you fly is usually not a full day anywhere. That 35 is my arithmetic on the IRS's rules, and it is the number I would plan around.

Three things follow.

Your 2026 is not lost. Once you reach 330 full days inside the window, you qualify for 2026 too, because the period only has to include "some part of the year at issue." You do not get the full $132,900 for 2026, though. When you meet the test for only part of a tax year, Publication 54 says "you must prorate the maximum exclusion based on the number of days that you did meet either test during the year." Form 2555 does it by dividing the days of your qualifying period that fall in the tax year by the days in that year. September 2 to December 31 is 121 days, so your 2026 maximum is 121/365 of $132,900, about $44,000. That is my arithmetic on the form's own formula.

The date that matters is your 330th full day. In this example, with no trips at all, that is July 28, 2027 by my count, and every day you spend outside a foreign country pushes it later. December 31 does not move it.

Your 2026 return is due before you qualify. If, on the regular due date, you live outside the US and Puerto Rico and your tax home is outside them too, you get an automatic extension to June 15, though interest on any tax due still runs from April 15. In this example, June 15, 2027 arrives well before your 330th day.

The extension built for exactly this

Form 2350 is an application for extension of time to file, for people who expect to meet one of the two tests, but not until after their return is due. Publication 54 says to request it if all three of these apply:

1. You are a US citizen or resident alien.
2. You expect to meet one of the two tests, but not until after your tax return is due.
3. Your tax home is in a foreign country throughout your period of residence or presence.

If it is granted, the extension is generally for 30 days beyond the date you can reasonably expect to qualify. You have to file Form 2350 by the due date of your return.

The other route is to file on time without the exclusion. Then you report your worldwide income and pay tax on it, and if you later meet the test, you file an amended return, Form 1040-X, with Form 2555 to claim the exclusion.

Which route fits depends on how much tax is at stake and how certain your dates are. That is a question for a tax professional who prepares Form 2555.

What the 330 days do not forgive

The test is mechanical, and the IRS is blunt about it. You do not meet it if you fall short of 330 full days "regardless of the reason for the failure, including illness, family problems, a vacation, or your employer's orders."

Publication 54 includes the example nobody wants to be: someone who went abroad on August 13 expecting to stay a year, was reassigned home and left on July 1. The IRS's answer is "You can't exclude any of the income you earned," because the 330 full days were never reached. The one exception is a waiver for people forced out of a country by war, civil unrest or similar conditions, for the countries the IRS lists each year.

Two more details catch people out. US territories are not foreign countries, so days in one do not count. And days only count while your tax home is abroad. The IRS lets you count days abroad "for any reason, so long as your tax home is in a foreign country," and your tax home is generally your principal place of business or employment.

When December 31 does matter

December 31 is where one tax year's share of the exclusion stops and the next one's starts. It decides how much you can exclude for each year, not whether you pass.

The flexibility works at the other end of a stay too. In the IRS's own example, someone lived and worked in New Zealand from January 1, 2024 through August 31, 2025, with 28 days in the US each February. For 2025 they could choose September 1, 2024 to August 31, 2025 as their period, overlapping the one they used for 2024. If you are moving home, your last window can end the day you leave.

What I would do with this

Write down your first full day abroad, not your arrival date. Every count starts there.

Log every border crossing as you go, with the times you left and landed. Rebuilding it from a passport the following spring is how a count goes wrong.

Budget your 35 days before you book the holidays. A two-week trip home costs more than 14 of them once the flight days are counted.

If you moved this year, decide on Form 2350 before your return is due, not after. Ask a tax professional which route fits your numbers.

The calendar is the wrong clock. Count full days, in the 12 months you choose, with your tax home abroad the whole time.

Sources: IRS Publication 54, Tax Guide for U.S. Citizens and Resident Aliens Abroad (Rev. December 2025). IRS, "Foreign earned income exclusion - Physical presence test" (page last reviewed March 14, 2026). IRS Form 2555 and its 2025 instructions, for the part-year proration. IRS Revenue Procedure 2025-32, section 4.39, for the 2026 exclusion amount of $132,900.