You get extra time to file and pay Minnesota income tax while you are serving, and a spouse who files jointly with you gets the same extension. Serving in a combat zone gives you 180 days from the day you leave it, or 180 days from your hospital discharge if you were hospitalized for injuries received there. Stationed outside the U.S. but not in combat operations, you have until October 15 of the tax year, as long as you pay 90 percent of any tax owed by April 15. A reserve component member called to federal active duty gets six months, or the time spent abroad plus six months when serving outside the U.S.
There is nothing to file in advance. File and pay by the extended date and tell the Minnesota Department of Revenue you are claiming a military filing extension.
Your orders showing the combat zone service, overseas station or federal active duty call-up, and hospital discharge paperwork if you are claiming the hospitalization extension.