Question 1

How does the 548-day rule work?

Accepted Answer

A New York domiciliary is treated as a nonresident if, within any period of 548 consecutive days: they are present in a foreign country or countries on at least 450 days; they spend no more than 90 days in New York during the period; and their spouse and minor children spend no more than 90 days at a New York permanent place of abode. Partial-year windows are prorated. (Sources: Tax Law § 605(b); Matter of Lynch (Tax Appeals Tribunal 2025).)

Question 2

Do travel days and days in the U.S. outside New York count toward the 450?

Accepted Answer

No — the 450-day count requires presence IN a foreign country. Days in other U.S. states, days at sea, and airport-transit days that don't land you in a foreign country do not count toward 450 (though they also don't count against your 90 New York days). This is where taxpayers most often fail the test. (Sources: Tax Law § 605(b); Matter of Lynch (Tax Appeals Tribunal 2025).)

Question 3

What happens if I miss one element — say my spouse spends 95 days at our New York apartment?

Accepted Answer

The test fails entirely and you remain a New York resident domiciliary for the period; there is no substantial-compliance doctrine. In Matter of Lynch (2025), the Tribunal applied the elements strictly. Track every day contemporaneously for yourself, your spouse and minor children. (Sources: Matter of Lynch (Tax Appeals Tribunal 2025); Tax Law § 605(b).)

A long posting abroad can suspend New York residency — if you hit every element of the 548-day test.