What counts as a day in Colorado for the six-month rule?

Colorado measures time spent in the state in aggregate across the tax year. Any part of a day present in Colorado generally counts toward the total, and the days do not need to be consecutive. You do not need to sleep at the permanent place of abode for time in the state to count.

Colorado's Six-Month (183-Day) Statutory Residency Rule

Q: How many days can you spend in Colorado without becoming a statutory resident?

Up to six months (183 days) in the tax year. Spending more than six months, roughly 184 days or more, in Colorado while maintaining a permanent place of abode there makes you a statutory resident even if you are domiciled elsewhere. At or under half the year keeps you under the day test.

Q: Do you need a home in Colorado to be a statutory resident?

Yes. The statutory residence test requires both a permanent place of abode in Colorado and more than six months of the tax year spent there. A permanent place of abode can be a house, condominium, apartment, room, or mobile home, and you need not own or lease it yourself. Days alone, without a qualifying place of abode, do not make you a statutory resident, though separate domicile rules can.

A home in Colorado plus more than six months there in the tax year makes you a statutory resident, even if you live elsewhere. Here is exactly how the count works.

Last verified: July 2026

In short: Colorado treats you as a statutory resident if you both maintain a permanent place of abode in the state and spend, in aggregate, more than six months (more than 183 days) in Colorado during the tax year. This applies even if your permanent home is in another state or country. Time is measured across the whole year, and the days do not need to be consecutive.

Threshold: More than 183 days (more than 6 months)
Also required: Permanent place of abode
Counting window: Tax year (calendar year)
Days counted: In aggregate across the year
Applies even if: Domiciled elsewhere
Legal basis: Colo. Rev. Stat. §39-22-103(8)

The rule

Colorado has two separate ways to be a resident: by domicile (Colorado is your true, permanent home) or by statutory residence. The six-month rule is the statutory-residence test, and it has two conditions that must both be met:

A permanent place of abode. You maintain a dwelling in Colorado. This can be a house, condominium, apartment, room in a house, or mobile home. You do not have to own it or be liable for the lease or mortgage yourself.
More than six months. You spend, in aggregate, more than six months (more than 183 days) of the tax year in Colorado. At or under half the year keeps you under the day test.

Meet both and you are a statutory resident, taxed by Colorado on your worldwide income, even if you are domiciled in another state or country.

How to count it

Confirm you maintained a permanent place of abode in Colorado during the tax year.
Count the time you were present in Colorado, in aggregate, across the year.
Add the days across the whole tax year. Days do not need to be consecutive.
If the total exceeds six months (more than 183 days) and the place-of-abode condition is met, you are a statutory resident for that year.

Example. You are domiciled in Texas but keep a condominium in Denver all year. Across the year you are physically in Colorado for roughly seven months, spread over many separate trips.

Because time is measured in aggregate, those separate stays add up. With a permanent place of abode plus more than six months in the state, you are a Colorado statutory resident, taxed on your full income, despite being a Texas domiciliary.

Beyond the day count

The six-month test is only the statutory route. Colorado can also tax you as a resident by domicile, which turns on where your true home and life are rather than a day count. A person can be domiciled in Colorado and remain a resident even while spending long stretches outside the state. The place-of-abode standard is broad: a room in a house or an employer-provided apartment can qualify, and you need not be the one paying for it.

Official source: Colorado Revised Statutes §39-22-103(8), explained by the Colorado Department of Revenue in its Individual Income Tax Guide.

AtlasDays tracks Colorado's 6-month residency rule automatically

Log your trips once. AtlasDays counts your days in Colorado for each tax year, privately on your iPhone, and warns you before you cross the six-month line.

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FAQ

How many days can you spend in Colorado without becoming a statutory resident?

Up to six months (183 days) in the tax year. Beyond that, combined with a permanent place of abode, you become a statutory resident even if domiciled elsewhere.

What counts as time spent in Colorado?

Colorado measures time in the state in aggregate across the tax year. Separate trips add up, and the days do not need to be consecutive.

Do you need a home in Colorado to be caught by the rule?

For the statutory test, yes. A permanent place of abode can be a house, condominium, apartment, room, or mobile home, and you need not own or lease it yourself. Without one there is no statutory residence on days alone, though separate domicile rules can still make you a resident.