M15: Underpayment of Estimated Income Tax (2025)
Minnesota · Minnesota DOR · Used for tax years 2025
Minnesota Schedule M15 determines whether you owe a penalty for underpaying estimated individual income tax for 2025 and calculates the penalty. It uses your tax liability, withholding, credits, and estimated tax payments and must be included with Form M1.
Who files this form
Use 2025 Schedule M15 to determine whether you owe a penalty for underpaying Minnesota estimated income tax. You may owe a penalty if you have $500 or more of Minnesota income tax due on 2025 income after subtracting withholding, estimated tax payments, and eligible refundable credits you claim.
You do not owe an underpayment penalty if all three apply:
- You had no Minnesota tax liability on line 17 of your 2024 Form M1.
- You were a Minnesota resident for all of 2024.
- Your 2024 return covered 12 months.
Farmers and commercial fishermen do not have to complete Schedule M15 if they filed Form M1 and paid their entire tax by March 1, 2026, or paid two-thirds of their tax by January 15, 2026. This rule applies if at least two-thirds of annual gross income comes from farming or commercial fishing.
Do not complete Schedule M15 if the IRS excuses federal underpayment charges because you are newly retired or disabled, or because of a casualty, disaster, or other unusual circumstances. Include a copy of your federal request with Form M1.
When it's due
For tax year 2025, the regular-method estimated payment due dates printed on Schedule M15 are:
- April 15, 2025
- June 16, 2025
- September 15, 2025
- January 15, 2026
Other dates relevant to the 2025 penalty calculation:
- January 31, 2026: If you filed your 2025 Minnesota return and paid the tax owed by this date, you may treat the tax as paid on January 15, 2026.
- March 1, 2026: Farmers and commercial fishermen can avoid completing the schedule by filing Form M1 and paying their entire tax by this date. The alternative is paying two-thirds of their tax by January 15, 2026.
- April 15, 2026: This is the cutoff date used in the penalty calculations. Under the short method, line 11 is zero if the underpayment will be paid on or after this date.
What you'll need
Have these forms and payment details available:
- 2025 Form M1: Schedule M15 uses your Minnesota tax, withholding, and credits from this return.
- 2024 Form M1, if filed: Used to determine your prior-year Minnesota tax liability and any refund applied to 2025 estimated tax.
- 2024 federal Form 1040: Line 11 provides the federal adjusted gross income used for the $150,000 test in the line 5 instructions.
- 2025 estimated tax payment amounts and dates: Include payments for 2025 made during 2025 and 2026.
If you use the annualized income installment method, you also need Schedule AI of federal Form 2210 and your income, deductions, additions, and subtractions for the periods shown in the worksheet. If Minnesota alternative minimum tax applies, see Schedule M1MT.
If you qualify for the federal underpayment-charge exception described in the instructions, include a copy of your federal request with Form M1.
How to file
Include Schedule M15 with your Form M1. The supplied text does not provide a mailing address or e-file directions.
Complete lines 1 through 6 first, following the stop instructions. If you need to continue, use either the optional short method or the regular method, as allowed by the instructions.
Enter the penalty from Schedule M15 line 12 or line 22 on line 27 of your 2025 Form M1. If you owe tax on Form M1 line 26, add the penalty and replace line 26 with the total. If you have a refund on line 24, subtract the penalty and replace line 24 with the result.
Common mistakes
- Continuing past a stop instruction: You do not owe a penalty if line 3 is less than $500, line 6 is no more than line 2, or short-method line 9 is zero or less.
- Using the short method when payments were early: The instructions warn that this produces a larger penalty than the regular method. The difference may be small if a payment was only a few days early.
- Including other amounts on line 7: Enter only estimated tax payments for 2025 made in 2025 and 2026.
- Using annualized installments for only some due dates: If you use the annualized income installment method for one payment due date, you must use it for all payment due dates.
- Carrying an overpayment forward before covering earlier shortages: An overpayment in a later quarter must first cover previous underpayments.
- Leaving out the schedule: The form says you must include Schedule M15 with Form M1.
Questions people ask
How much must I pay to avoid an underpayment penalty?
Through withholding or timely estimated payments, pay the lesser of 90% of your current-year original tax liability or 100% of your prior-year total tax liability. The current-year percentage is 66.7% for farmers and commercial fishermen. The prior-year percentage is 110% if your federal adjusted gross income is more than $150,000. Nonresidents and part-year residents must have at least $1 of prior-year Minnesota tax liability to use the prior-year rule.
Who can use the optional short method?
You may use it if you made no estimated payments, including when your only payments were Minnesota wage withholding, or if you paid your 2025 estimated tax in four equal amounts by each installment due date.
What if I did not file a 2024 return?
Skip line 5 and enter the amount from line 4 on line 6. Do the same if your 2024 return did not cover a full 12-month period.
What if my income varied during the year?
You may benefit from the annualized income installment method. Complete the worksheet on the back of Schedule M15. If you use this method for one payment due date, you must use it for all payment due dates.
How is a 2024 refund applied to 2025 estimated tax treated?
If you elected to apply all or part of your 2024 Minnesota refund to 2025 estimated tax, it is treated as a payment for the first payment period.