How to Fill Out and File Minnesota Schedule M1SA: Itemized Deductions

Minnesota Schedule M1SA is the form you attach to your Form M1 state return when you want to deduct specific personal expenses instead of taking the flat standard deduction. The total from M1SA flows to line 4 of Form M1.¹ You can itemize on your Minnesota return even if you took the standard deduction federally, and vice versa; the state decoupled from the federal choice, so pick whichever method saves you more on each return separately.² The form covers six categories: medical and dental costs, state and local taxes, interest, charitable gifts, casualty losses, and unreimbursed employee expenses.

Should You Itemize on Your Minnesota Return

Itemizing only pays off if your qualifying expenses beat the standard deduction for your filing status. For tax year 2026, Minnesota’s standard deduction amounts are:³

Married filing jointly or surviving spouse: $30,600
Head of household: $23,000
Single or married filing separately: $15,300

One trap: if you’re married filing separately and your spouse itemizes on their Minnesota return, you must itemize too, even if the standard deduction would be larger for you.¹ Homeowners with a mortgage and significant property tax bills are the most likely to clear the threshold, especially when combined with charitable giving. Run the numbers both ways before you commit.

Medical and Dental Expenses

You can deduct medical and dental costs that exceed 10% of your adjusted gross income (the figure on line 1 of Form M1). Minnesota holds this floor at 10% regardless of whatever percentage the federal return uses.² On a $60,000 AGI, only the portion of medical expenses above $6,000 counts.

Qualifying costs include doctor and dentist visits, prescription drugs, health insurance premiums paid with after-tax dollars, eyeglasses, and long-term care expenses. If you filed a federal Schedule A, you can carry the same medical total to M1SA, but the 10% floor is recalculated on the Minnesota form using your Minnesota AGI.¹ Subtract any insurance reimbursements before you enter the total. Keep receipts, explanation-of-benefits statements, and pharmacy records.

State and Local Taxes

Your deduction for real estate taxes and personal property taxes is capped at a combined $10,000, or $5,000 if you’re married filing separately.² This cap is set in Minnesota’s own statute and applies regardless of your federal deduction. Real estate taxes qualify only if they were uniformly assessed and used for general government purposes; special assessments for sidewalks, sewers, and similar local improvements don’t count.¹

Personal property taxes (such as the tax portion of your vehicle registration) are deductible only if they’re based on the property’s value and imposed annually. A separate line handles other deductible taxes, like income tax paid to a foreign country. You do not deduct Minnesota income tax on your Minnesota return.

Pull your county property tax statement and any personal property tax receipts. If you filed a federal Schedule A, the amounts on lines 5b and 5c carry over to the corresponding M1SA lines, though the cap recalculates independently.

Interest You Paid

Home mortgage interest is the biggest item here for most filers. Minnesota follows the federal rules under IRC Section 163 with a few state-level exceptions.² For mortgages taken out on or after December 16, 2017, you can deduct interest on up to $750,000 of acquisition debt ($375,000 if married filing separately). Older mortgages follow the $1 million limit. Your lender’s Form 1098 has the exact interest figure.

Two Minnesota-specific rules trip people up. Home equity loan interest is not deductible on M1SA even when the federal return allows it. And private mortgage insurance premiums are not treated as deductible interest for Minnesota purposes, which breaks from the current federal treatment of PMI as interest.² If you paid PMI and deducted it federally, do not carry that amount to M1SA.

Investment interest (interest paid on money borrowed to buy taxable investments) is also deductible, but may require you to complete and attach a federal Form 4952 calculated for Minnesota purposes.¹

Charitable Contributions

Minnesota follows the federal rules for charitable giving under IRC Section 170.² Cash gifts to qualifying religious, educational, scientific, and charitable organizations count. Non-cash donations like clothing, household goods, and vehicles qualify too, but you need to document fair market value carefully.

For any single contribution of $250 or more, you need a written acknowledgment from the organization that includes the amount, the date, and whether you received anything in return. Keep bank statements or cancelled checks for cash gifts and written receipts for non-cash donations. If you’re carrying forward excess contributions from a prior year, the carryover is based on what you actually claimed on past M1SA schedules, not your federal returns.²

Casualty and Theft Losses

If you suffered property damage from a sudden, unexpected event during the tax year, you may be able to deduct the unreimbursed loss. To claim it on M1SA, complete Schedule M1CAT and attach it to your return.¹ Starting in 2026, the federal rules expanded to cover losses from disasters recognized by both a state governor and the U.S. Secretary of the Treasury, not just presidentially declared disasters.⁴ Keep insurance claim documentation, repair estimates, and photos to support the amount you enter.

Unreimbursed Employee Expenses

This is where Minnesota diverges most from the federal return. The federal code suspended the deduction for unreimbursed employee business expenses after 2017, but Minnesota still allows it.⁵ You can deduct work-related costs your employer didn’t reimburse, but only the portion that exceeds 2% of your AGI.²

Complete Schedule M1UE and attach it; the total feeds into Schedule M1SA.⁶ Qualifying expenses include business mileage (standard rate or actual costs), overnight business travel and lodging, tools and supplies your employer didn’t provide, job-related education, a qualifying home office, and union dues and professional memberships.

One exception to the 2% floor: if you have a disability and claimed impairment-related work expenses on federal Form 2106, those expenses go on a separate line of M1SA and are not subject to the threshold.⁶

Phase-Out at Higher Incomes

Higher-income filers don’t get the full benefit. Minnesota reduces your total itemized deductions once your income crosses certain thresholds. For tax year 2026:³

First threshold: $244,400 ($122,200 for married filing separately)
Second threshold: $337,800 ($168,900 for married filing separately)
At income of $1,107,750, the reduction stops; you keep at least 80% of your itemized deductions no matter how high your income goes

Between the first and second thresholds the reduction phases in gradually. If you’re near or above these income levels, the arithmetic gets involved enough that tax software or a preparer earns its keep. The phase-out happens on Form M1 itself, not on M1SA, so your M1SA total reflects the full amount before any reduction.

Filing Schedule M1SA

Schedule M1SA doesn’t file on its own. It attaches to your Form M1, with the M1SA total transferring to line 4.¹ If you claim casualty losses or unreimbursed employee expenses, Schedules M1CAT and M1UE have to go along with it.

E-filing is faster and reduces errors. The Minnesota Department of Revenue certifies several free e-file software options through the IRS Free File program, with eligibility generally based on AGI thresholds.⁷ Commercial tax software handles M1SA automatically, transmitting the schedule with your return. Paper filers mail Form M1 with all supporting schedules to Minnesota Revenue, Mail Station 0010, 600 N. Robert St., St. Paul, MN 55146-0010.⁸

The deadline for tax year 2026 returns is April 15, 2027. An automatic extension pushes the filing date to October 15, 2027, but only for filing; any tax owed is still due by April 15 to avoid interest.

How Long to Keep the Supporting Records

Hold onto every receipt, Form 1098, property tax statement, charity acknowledgment letter, and M1UE log for at least three and a half years after the filing date or the return’s due date, whichever is later. That’s the standard window the Department of Revenue has to review your return under Minnesota’s statute of limitations.⁹

Keep records for six and a half years if you omitted more than 25% of your gross income, if you or the IRS amended a return, or if the records relate to property basis that could matter on a future return.¹⁰ If you filed a fraudulent return or didn’t file at all, there’s no time limit on assessment.⁹

1
Minnesota Department of Revenue. 2025 Schedule M1SA, Minnesota Itemized Deductions
2
Minnesota Office of the Revisor of Statutes. Minnesota Code 290.0122 – Itemized Deductions
3
Minnesota Department of Revenue. Tax Year 2026 Inflation-Adjusted Amounts
4
Congress.gov. The Nonbusiness Casualty Loss Deduction
5
Minnesota Department of Revenue. Tax Tip #7 for Tax Professionals – Itemized Deductions for Minnesota
6
Minnesota Department of Revenue. 2025 Schedule M1UE, Unreimbursed Employee Business Expenses
7
Minnesota Department of Revenue. Free Electronic Filing
8
Minnesota Department of Revenue. File an Income Tax Return
9
Minnesota Office of the Revisor of Statutes. Minnesota Code 289A.38 – Limitations on Time for Assessment of Tax
10
Minnesota Department of Revenue. Record-keeping for Income Tax Purposes