This section provides scenarios for certain people in Idaho, their residency status, and what that means for filing Idaho income tax returns.
Absent from Idaho for 445 days in a 15-month period
Some people domiciled in Idaho can be treated as nonresidents. Idaho allows an exception to being a resident if you were out of Idaho for at least 445 days in a 15-month period. In this case, you’re not considered to be an Idaho resident and may not have to file an Idaho income tax return.
But the 445-day absence exception isn’t available if:
- You have a permanent home in Idaho where your spouse or minor children live for more than 60 days during the calendar year.
- You claim Idaho as your tax home for claiming “away-from-home” expenses on your federal return.
- You’re employed on the staff of a U.S. Senator or Representative.
- You hold an elected or appointed office of the U.S. Government other than the armed forces or career appointment in the U.S. Foreign Service.
When you’ll be an Idaho resident again
After you initially satisfy the 445-day absence test, you’ll be considered an Idaho resident again if at any point you’re in Idaho more than 60 days in any calendar year.
John is single and is domiciled in Idaho. He works for a construction company that assigned him to a three-year project in Alaska. John will return to Idaho when the work completes. He claimed Alaska as his tax home for federal income tax purposes. John left Idaho on July 15, 2014. He was in Idaho from March 20, 2015 through March 27, 2015, and from December 15, 2016 through December 30, 2016. John returned to his home in Idaho on September 30, 2017 when the project he was working on wrapped up. He stayed in Idaho through the end of 2017.
- John’s initial 15-month period started July 15, 2014.
- 2014: John was a part-year resident. He was a resident of Idaho from Jan. 1 – July 14. He was a nonresident from July 15 – Dec. 31.
- 2015: John was a nonresident. He didn’t have to file an Idaho income tax return because he was absent from Idaho for 450 days in the first 15-month period – July 15, 2014, through October 15, 2015 and didn’t have any Idaho source income.
- 2016: John was again a nonresident.
- 2017: John was a part-year resident. From Jan. 1 – Sept. 29 he was a nonresident. He became a resident again on September 30, 2017. This is the date he returned to Idaho and remained for more than 60 days.
If John was married:
If his wife stayed at home in Idaho, John wouldn’t qualify for nonresident status. He’d be an Idaho resident for 2014-2017 because he was domiciled in Idaho. (This example also applies to people working out of the country.)
In the military
Your military home of record might not be where you’re domiciled. Typically, your state of legal residence is also your state of domicile, but this could be different from your home of record. If you’re stationed in Idaho on active military duty, you’re considered a resident of the state where you’re domiciled.
- If Idaho is where you’re domiciled, you’re an Idaho resident.
- If your domicile is another state, you’re a military nonresident.
- Active duty military pay isn’t taxed.
- Military nonresidents are taxed on other income received from Idaho sources.
A nonmilitary spouse living in Idaho can be a resident, part-year resident, or a nonresident.
Gary and his wife, Linda, are domiciled in Alabama. Gary is in the Air Force and claims Alabama as his home of record. In October 2016, Gary was transferred to Mountain Home Air Force Base. They both moved to Idaho and stayed in Idaho during 2017. Since Gary’s domicile isn’t Idaho, he’s a military nonresident. But if Gary changes his domicile to Idaho, he’d be an Idaho resident.
Since Linda had the same domicile as Gary, she is a nonresident while in Idaho unless she changes her domicile to Idaho. She’d be an Idaho resident or part-year resident depending on the date her domicile changed.
Transportation employees
Federal laws limit states from taxing compensation of certain types of employees. You’re subject to income tax only in your state of residence if:
- You’re an interstate rail or motor carrier employee, and
- You have regularly assigned duties in more than one state.
This exclusion doesn’t apply to government employees. The part of your income earned in Idaho is taxable to Idaho.
People who move for seasonal work
A married couple, Don and Diane, have a fishing business and a home in Alaska. They also have a home in Idaho where they live during the off season. They have both registered to vote in Idaho.
They live in Idaho at least part of the year, so they’re either residents or part-year residents.
They’ll need to determine where their domicile is.
If Don and Diane are domiciled in Idaho — or lived in Idaho more than 270 days (even though they’re domiciled in Alaska) — they’re considered Idaho residents.
Spouses who live and work in different states
Spouses can have separate residences and domiciles.
Cindy lives and works in Idaho. Craig lives and works in Washington. They’re married.
Cindy is an Idaho resident. Craig could be an Idaho resident if he’s domiciled in Idaho.
If they file a joint return for federal income tax purposes, they must file a joint return for Idaho. If Craig isn’t a resident of Idaho, they must file using an Idaho 
Form 43, Idaho Part-year Resident & Nonresident Income Tax Return. Craig would be listed as a nonresident. Cindy would be listed as a resident.
Retired people traveling in a motorhome
Vern and Vera retired recently. They were residents of Idaho and domiciled here. Since retiring, they've sold their Idaho home and bought a motor home. They plan to travel around the country.
Idaho will continue to be their domicile until they establish a new one. Since they'll be traveling around the country and have no intention to establish a new domicile, Idaho remains their domicile. They'll continue to be Idaho residents and all income is taxable to Idaho.