If your spouse is in the military, you likely move from state to state. Generally speaking, the state that you live and work in during any given tax year is the state in which you are required to pay taxes. Your Form W-4, which tells your employer how much to withhold from your wages, should reflect that. However, the Military Spouses Residency Relief Act of 2009, makes an exception to this rule. The act covers military spouses who are living and working in one state due to Armed Forces duty, but whose permanent residence is in another state.
Count your military spouse as fully employed if your spouse is not serving in a combat zone. According to the Internal Revenue Service (IRS) web page on military pay exclusion, any pay earned by a member of the Armed Forces in a non-combat zone is taxable and should be considered income. On a Form W-4, you can acknowledge your spouse's military income by marking a "0" or “1” in line “C” of the W-4.
Mark your spouse as having income of under $1,500 on the W-4 if your spouse has spent the year serving in a combat zone. According to the IRS regarding military pay exclusion, income earned during any month spent working in a combat zone is excluded from gross income. To mark your spouse as earning less than $1,500 on the W-4, put a “1” in line “B.”
Complete the “Two-Earners/Multiple Jobs Worksheet” only if your spouse is working outside of a combat zone. This section includes both your income and that of your military spouse, and helps your employer withhold the correct amount of taxes. If your spouse is in a combat zone, the income isn’t taxable, so you don’t need to include it on your W-4 to have additional taxes withheld.
Check the box regarding the Military Spouses Residency Relief Act if one is available for you on the form and you are a military spouse who has a permanent residence in another state. Some states, like Iowa and Connecticut, have added check boxes directly to their Form W-4. If that's the case in the state where you now are working, mark the box and enter the name of the state where your permanent residence is located.
Most of the states that do not have check boxes for the Military Spouses Residency Relief Act on their Form W-4 provide a separate form to fill out for this program. Some states, however, require you to write your exempt status at the top of your W-4. When in doubt, it’s best to ask your employer how you claim exempt status.