H-1B Substantial Presence Test 2026 Calculator

The substantial presence test (SPT) determines whether an H-1B worker is a US tax resident for 2026. Under IRC Section 7701(b)(3) and IRS Publication 519, you are a resident if you are physically present in the United States for at least 31 days in 2026 AND your weighted day count across 2026, 2025, and 2024 reaches 183. Resident aliens are taxed on worldwide income; nonresident aliens only on US-source income.

How the SPT Formula Works

The weighted formula: (Days 2026 x 1) + (Days 2025 x 1/3) + (Days 2024 x 1/6). Round fractional days down. If the sum is 183 or more — and you spent at least 31 days in 2026 — you meet the SPT and file Form 1040 as a resident alien. If you miss either threshold, you file Form 1040-NR as a nonresident. Most H-1B holders who arrived in mid-year still pass: 240 days in 2026 alone exceeds 183.

First-Year Choice and Dual-Status Years

H-1B workers arriving mid-year often hit a dual-status year: nonresident before arrival, resident after meeting SPT. You file 1040 (showing the resident portion) with a 1040-NR statement attached. The First-Year Choice under IRC Section 7701(b)(4) lets you elect resident status earlier if you're present at least 31 consecutive days in 2026 and 75% of days from that start through year-end. Spouses can elect joint resident filing under Section 6013(g) or 6013(h).

Treaty Tie-Breaker Override

Even if SPT makes you a US resident, a tax treaty tie-breaker (per OECD Model Article 4 or country-specific articles like India-US Article 4) can override and treat you as a resident of your home country. The hierarchy: permanent home → center of vital interests → habitual abode → nationality. India, UK, Canada, China, Germany, France all have these. Claim the treaty via Form 8833. Note: treaty residency only affects income tax, not FICA (still owe US Social Security and Medicare on H-1B wages).

Common H-1B Tax Filing Mistakes

(1) Forgetting partial-day rules — any day with even a moment in the US counts as a full day except for transit (under 24 hours airport stops). (2) Missing the 31-day minimum — if you arrived December 15 with only 17 days, you fail SPT regardless of weighted total. (3) Not reporting foreign accounts — once a US resident, you must file FBAR (FinCEN 114) if foreign accounts exceed $10,000 and Form 8938 at higher thresholds. (4) Forgetting state residency — states like California test residency separately. Sources: IRS Publication 519 (US Tax Guide for Aliens, 2025), IRC Sections 7701(b) and 6013, OECD Model Tax Convention Article 4.

Last updated May 2026. Sources cited in tool output.