Connecticut — Tax Residency Rule

Summary

Day threshold

More than 183 days

Window

Calendar year

Also requires

A permanent place of abode in CT

Effect

Worldwide income taxed

Basis

Chapter 229, CT General Statutes

Connecticut treats you as a statutory resident for income tax if both are true in the same calendar year: you spend more than 183 days in the state and you maintain a permanent place of abode there. To stay outside this rule, keep your Connecticut days at 183 or fewer, or avoid keeping a permanent abode in the state. A separate domicile test can make you a resident even below the threshold.

Who it applies to

This matters most if you are:

• A remote worker or frequent traveler spending long stretches in Connecticut each year.
• Someone who keeps an apartment or second home in Connecticut while living or working elsewhere.
• A person moving to or from Connecticut mid-year, where days and abode overlap for part of the year.
• Anyone whose true, fixed, permanent home (domicile) is arguably in Connecticut.

It applies to individuals based on presence and housing, not citizenship or visa status. The rule sits alongside — and is separate from — the federal US tax rules.

The rule — and why it exists

Connecticut's income tax law defines residency through two independent routes:

• Statutory residency (the day-count route). More than 183 days in Connecticut during the calendar year plus a permanent place of abode in the state makes you a resident, whatever your domicile.
• Domicile. If Connecticut is your true, fixed, permanent home, you are a resident regardless of day count, unless you meet strict tests to establish a domicile elsewhere.

Why it exists: states use physical presence and a maintained home as proxies for where your economic life really sits. Pairing the day count with an abode requirement stops people who genuinely base themselves in Connecticut from sidestepping residency by claiming a home elsewhere, while the abode condition keeps a mere visitor with no home out of the net.

Counting the days

1. 1Count each day, or part of a day, you are physically present in Connecticut during the calendar year (1 January to 31 December).
2. 2The count resets to zero at the start of each new calendar year — it is a fresh annual tally, not a rolling window.
3. 3Any part of a day generally counts as a full day, unless you are only passing through in transit.
4. 4You become a statutory resident once you exceed 183 days while also holding a permanent place of abode in the state.

Because the window is the calendar year, a stay split across a year-end can leave you under the threshold in each individual year even if the trip itself is longer.

Examples

Example 1 — clearly resident by days

You rent a year-round apartment in Stamford and are physically present in Connecticut for about 210 days in the year. You exceed 183 days and hold a permanent abode, so you are a statutory resident and Connecticut can tax your worldwide income for that year.

Example 2 — over 183 days but no abode

You spend 200 days in Connecticut but always stay in short-term hotels and keep no dwelling suited to year-round living. The abode condition is not met, so the statutory-residency rule does not apply — though domicile could still be examined separately.

Example 3 — resident by domicile below the threshold

Connecticut is your true, fixed, permanent home, but work sends you abroad and you spend only ~90 days in the state. You are under 183 days, yet you can still be taxed as a resident because your domicile remains in Connecticut.

Exceptions & edge cases

• Domicile overrides the day count. A Connecticut domicile makes you a resident below 183 days; the day-count route is only one of two ways in.
• The abode must be genuinely permanent. A place kept only briefly, or a property not suited to year-round living, generally does not count, so more than 183 days alone need not trigger the rule.
• Credit for other states' tax. A resident taxed by another state on the same income may claim a credit, reducing double taxation even while remaining a Connecticut resident.
• Part-year moves. Moving into or out of Connecticut mid-year can create a part-year residency, changing how days and abode are assessed for the year of the move.

Common misconceptions

• "Under 183 days means I'm safe." False — a Connecticut domicile makes you a resident with any number of days.
• "More than 183 days always makes me a resident." Not on its own — the statutory route also requires a permanent place of abode in the state.
• "Only Connecticut income is taxed." A resident is taxed on worldwide income for the year, subject to a credit for tax paid to other states.
• "The 183 days must be one continuous stay." No — it is a running tally of every day of presence across the whole calendar year.

Frequently asked questions

Sources

• CT General Assembly — Chapter 229, Income Tax
• CT Department of Revenue Services — Residency for tax purposes