Pilots and Flight Crew: How Base Location and Layovers Affect Your Puerto Rico Day Count

Which Presence Test Fits a Flight Crew Schedule?

Your Puerto Rico day count runs on where you physically are each day. Not on which airport your paycheck lists as your base. A rotating schedule and international layovers change which of the presence test's five paths actually fits you, but none of them let you skip the test itself.

26 CFR 1.937-1 lays out five separate paths, and you only need one. The one most people reach for first, 183 days physically present in Puerto Rico during the year, is often the hardest for flight crew to hit cleanly. Duty time off island eats into it fast. The regulation offers four alternatives: 549 days present over the current year plus the two before it, with at least 60 days in each of those three years; no more than 90 days present in the United States during the year; US-source earned income under a set ceiling combined with more Puerto Rico days than US days; or no significant connection to the United States at all during the year.

If your duty roster puts you on the mainland or overseas more than a typical office job would, run the numbers on the 549-day path before assuming 183 days is your only option. It trades a stricter three-year minimum for more room within any single year, which can fit a schedule with a heavy month or two better than a strict annual threshold does. Publication 570 restates all five paths in plain language, and it's the place to check the current earned-income ceiling for the fourth path, since that figure isn't fixed by the regulation itself.

What Counts as a Day When You're Flying or on Layover?

A day of physical presence is any day you're in Puerto Rico at any point, even briefly. The same rule runs in reverse for the United States: any part of a day physically present there counts as a US presence day. There's a short list of exceptions built specifically for travel.

The one that matters most for flight crew is the transit rule. Under 26 CFR 1.937-1, a day spent in transit between two points outside the United States doesn't count as a US presence day, as long as you're physically in the United States for fewer than 24 hours during that transit. A short connection through a mainland airport on the way between Puerto Rico and an international destination falls inside that carve-out. A layover that runs longer, or a duty day that has you actually working or resting overnight in the United States, does not.

There's also a same-day tiebreaker. If you're physically present in both Puerto Rico and the United States on the same calendar day, 26 CFR 1.937-1 counts that day toward your Puerto Rico total, not your US total. A morning departure from San Juan on a day you land on the mainland by evening still counts as a Puerto Rico day. Publication 570 adds one more allowance worth knowing: if your Puerto Rico days already outnumber your US days for the year, up to 30 days spent traveling outside both places can still count toward your Puerto Rico total. For a deeper walkthrough of how these day-counting rules apply outside the flight-crew case, see what counts as a day in Puerto Rico.

What's Your Tax Home if You Don't Have One Base?

The tax home test asks a different question than the presence test. A rotating base doesn't answer it automatically, either way. 26 CFR 1.937-1 determines tax home under the principles of section 911(d)(3): your tax home is your regular or principal place of business, or the principal one if you have more than one regular location.

Flight crew often don't have a single regular place of business in that sense, and the regulation accounts for it. If the nature of the occupation means there's no regular or principal place of business at all, the tax home defaults to your regular place of abode in a real and substantial sense: where you actually live. Neither the regulation nor Publication 570 gives flight-crew-specific guidance here, so whether your assigned base counts as a genuine regular place of business, or whether the abode fallback applies instead, is a facts-and-circumstances question tied to your actual duty pattern. It doesn't resolve itself from your base airport code alone.

That fallback is also why a mainland base assignment isn't automatically disqualifying, and a San Juan base assignment isn't automatically sufficient. Either way, the tax home test runs separately from the presence test and the closer connection test, and all three have to be satisfied on their own terms. The presence test, tax home, and closer connection tests overview walks through how the three interact for a typical case.

Does the Airline's Foreign Airspace Paperwork Count Toward Any of This?

No. The IRS's guidance on flight crew performing services in foreign and international airspace governs a completely different question: whether your compensation qualifies for the foreign earned income exclusion under section 911. That exclusion apportions your pay between time spent in or over a foreign country and time spent over international waters, US airspace, or US territory, using duty-time percentages your airline may already calculate for you.

None of that apportionment plays a role in the Puerto Rico presence test or the tax home determination. Those run on section 937, a separate framework with its own day-counting rules. Duty-time apportionment tells you what fraction of a paycheck might qualify for a different exclusion. It doesn't tell you how many days you were present in Puerto Rico or the United States, and it doesn't answer where your tax home is under section 937. Treat the two as unrelated paperwork, even though both involve counting time you spent in the air.

What Records Should Flight Crew Keep?

The documentation an examiner asks for doesn't change because your schedule is irregular. What counts as good evidence looks different for flight crew than for someone who works from one office, though. A duty roster showing your assigned trips, together with boarding passes and any crew scheduling records your airline retains, does the same job a calendar does for someone with a fixed routine: it ties a specific day to a specific location, contemporaneously, not reconstructed months later.

Keeping this by hand is the part people abandon by the time an audit letter arrives. One83 builds that ledger from your calendar as the days happen, so the record exists before anyone asks for it. For the fuller picture of what an examiner typically requests, and how long to keep it, see documenting presence for an audit.

Frequently Asked Questions

Do my international layovers count against my Puerto Rico presence test?

A layover outside the United States is not a US presence day at all, so it does not work against the 90-day US limit path. It also is not a Puerto Rico presence day unless you are physically in Puerto Rico that day. What matters for the transit carve-out specifically is time spent in the United States: under 26 CFR 1.937-1, a day in transit between two non-US points does not count as a US presence day as long as you are physically in the US for fewer than 24 hours during that transit.

I don't have one fixed base. Does that hurt my tax home test?

Not automatically. The regulation's default rule looks for your regular or principal place of business, but it has a built-in fallback for occupations where that doesn't exist: your tax home becomes your regular place of abode in a real and substantial sense. A rotating base or reserve status pushes you toward that fallback question rather than resolving it against you, which is why keeping Puerto Rico as your actual home, not just a duty station, matters.

Does the IRS's foreign airspace guidance for pilots affect my Puerto Rico day count?

No. That guidance governs the section 911 foreign earned income exclusion and how crew compensation is apportioned between foreign and non-foreign airspace. Puerto Rico bona fide residency runs on section 937, a separate set of tests. Duty-time apportionment percentages from your airline have no bearing on your presence test day count or your tax home determination under section 937.

Can I pass the presence test if I'm technically based on the mainland but fly Puerto Rico routes?

Your base station is one fact among several, not the whole test. You would still need to independently satisfy one of the five presence test paths, meaning enough physical days in Puerto Rico or a qualifying alternative, and you would face the tax home and closer connection tests on their own terms. A mainland base makes the tax home test a harder case to make, since it points toward a regular place of business outside Puerto Rico, but the regulation's own abode fallback means it is not automatically disqualifying.

One83 is a tracking tool, not tax advice. Consult a licensed tax professional about your situation.