How Many Days Can You Stay in the US Without Becoming a Tax Resident?

The Substantial Presence Test, Closer Connection Exception, and treaty tie-breaker — the three lines an Italian must understand before increasing US presence.

Published: 2026-04-15 · Last verified: 2026-04-15 · 6 min · Author: Avv. Dott. Massimo Leonardi

The Substantial Presence Test

US tax residence is determined under IRC §7701(b). The Substantial Presence Test counts days physically present in the US:

• Full days in the current year × 1
• Full days in the prior year × 1/3
• Full days two years ago × 1/6

If the total ≥ 183 days and current-year days ≥ 31, you are a US tax resident for the current year.

Practical zones

Days/year (averaged) — Status

0-120 — Generally safe non-resident

121-180 — Year-by-year analysis required

181-220 — Likely US tax resident under SPT

221+ — US tax resident

A practical safe limit is approximately 120 days per year, averaged across three years.

Closer Connection Exception

Even if you cross the SPT, you can claim the Closer Connection Exception (Form 8840) if:

• Days in current year are fewer than 183
• You maintain a tax home in a foreign country
• You have a closer connection to that foreign country (home, family, banking, doctors)

This is the most common exit ramp for Italian high-net-worth travelers who spend extended winters in Florida.

Treaty tie-breaker

Under art. 4 of the Italy-USA Treaty, even when both countries claim residence, an ordered tie-breaker selects one:

• Permanent home
• Center of vital interests
• Habitual abode
• Citizenship
• Mutual agreement

The treaty tie-breaker requires Form 8833 disclosure, has consequences for treaty benefits, and is best deployed when SPT cannot be avoided.

Green Card overrides

Note: holding a US Green Card makes you a US tax resident regardless of physical presence. The day count rules don't help.

[LAST VERIFIED: 2026]

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• US Tax Obligations for Italians Resident in the USA — Comprehensive cross-border compliance: Form 1040, FBAR, Form 8938, 5471, 8865, 8621, 3520, 8854 — coordinated with Italian filings.

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About the firm

IIILEX International Consulting LLC is the Florida-based practice of Avv. Dott. Massimo Leonardi — Italian-qualified Attorney (Avvocato), Dottore Commercialista and Statutory Auditor (Revisore Legale), qualified in Italy. We work exclusively on cross-border matters between Italy and the United States, in coordination with licensed U.S. professionals for matters of U.S. law.

IIILEX International Consulting LLC · 1200 Brickell Ave, Suite 310, Miami, FL 33131 · us@3lex.us · +1 (786) 604-8763 · +39 335 344 9660

Versione italiana

Massimo Leonardi is admitted to practice law in Italy and is not admitted to practice law in Florida or elsewhere in the United States. He is qualified in Italy as Dottore Commercialista and Revisore Legale and is not a U.S. Certified Public Accountant. IIILEX International Consulting LLC provides cross-border consulting and Italian legal and tax advisory services. Matters requiring advice on U.S. or Florida law are handled in coordination with appropriately licensed U.S. professionals.