To claim a refund, you must file Form M1X within 3½ years of the original due date for your return. If you need a prior year form, see Find a Form.

You must notify the Minnesota Department of Revenue within 180 days. If you do not amend your Minnesota return or notify us as required, we will charge a 10% penalty on any additional tax you owe.

If the changes affect your Minnesota return, you must file Form M1X even if your refund or amount due does not change. Include a complete copy of your amended federal return or IRS correction notice. Send your amended return to:

Minnesota Amended Individual Income Tax
Mail Station 1060
600 N. Robert St.
St. Paul, MN 55146-1060

If the changes do not affect your Minnesota return, you must send us a letter of explanation and a complete copy of your federal amended return or IRS correction notice. Send this letter to:

Minnesota Department of Revenue
Mail Station 7703
600 N. Robert St.
St. Paul, MN 55146-7703

You must pay the amount due when you file Form M1X, or we will charge a late payment penalty. For payment options, see Make a Payment.

Yes. Starting with tax year 2025, you can file amended Minnesota Income Tax returns electronically if your software product offers this option. 

You may want to consult a tax professional when amending your tax return in the following situations:

• You are amending a joint tax return when you and your spouse are now divorced
• You are protecting your right to a potential refund in the future (filing a protective claim)

For details, see Amending a Return in Special Circumstances.