The Minnesota estate tax return is due nine months after the decedent's date of death, regardless of where the probate process currently stands. The personal representative of the estate is responsible for filing Form M706 (Minnesota Estate Tax Return) with the Minnesota Department of Revenue by that deadline. If more time is needed, an automatic six-month extension can be requested by filing before the original due date.

What Is the Minnesota Estate Tax Return?

Minnesota imposes its own state-level estate tax on estates that exceed the applicable exemption threshold. For deaths occurring in 2024, the Minnesota estate tax exemption is $3 million. Any estate valued above that amount at the time of death may owe state estate tax, separate from any federal estate tax liability.

Form M706 is the primary document used to report the estate's gross value, deductions, and the resulting tax owed. This form must be filed even if the estate ultimately owes no tax, provided the gross estate exceeds the exemption threshold. Filing requirements apply whether the estate goes through formal probate or is administered through other means.

When Does the Filing Deadline Apply During Probate?

The nine-month deadline is calculated from the date of death, not from the date probate was opened. Many personal representatives mistakenly believe the clock starts when they are appointed by the court. It does not. If probate is delayed or contested, the tax filing obligation still follows the original nine-month window.

This timing distinction matters because probate proceedings in Minnesota can take anywhere from several months to well over a year. Waiting for probate resolution before addressing estate tax filings is one of the most common and costly errors a personal representative can make.

How to Adjust Based on Your Estate's Specific Situation

Complex Estates With Multiple Asset Types

Estates that include real property in multiple states, business interests, or significant investment portfolios may require professional appraisals to establish fair market values. These valuations take time. If your estate involves hard-to-value assets, begin the appraisal process immediately after appointment rather than waiting until close to the filing deadline.

Estates With Disputes Among Heirs

Contested probate proceedings do not suspend the estate tax filing deadline. The personal representative should file Form M706 on time, even if asset distribution is unresolved. Overpaying the tax and filing an amended return later is far less damaging than incurring late-filing penalties and interest.

Non-Residents Owning Minnesota Property

If the decedent was not a Minnesota resident but owned real estate or tangible personal property within the state, a Minnesota estate tax return may still be required. The same nine-month deadline applies, but the taxable estate is limited to Minnesota-sited assets.

Common Mistakes and How to Avoid Them

  • Missing the deadline. Late filing triggers a penalty of 5% per month on the unpaid tax, up to 25%. Set calendar reminders from the date of death.
  • Confusing federal and state exemption amounts. The federal exemption ($13.61 million in 2024) is far higher than Minnesota's $3 million. An estate may owe Minnesota tax while owing nothing federally.
  • Failing to report life insurance proceeds. Proceeds payable to the estate or over which the decedent held incidents of ownership are included in the gross estate.
  • Not requesting an extension properly. The automatic six-month extension requires filing a request before the original due date and paying any estimated tax owed at that time.
  • Ignoring portability. Minnesota does not offer estate tax portability between spouses, unlike the federal system. Plan accordingly.

Quick Checklist for Personal Representatives

  1. Determine the date of death and mark the nine-month filing deadline.
  2. Inventory all assets and obtain professional valuations where needed.
  3. Confirm whether the gross estate exceeds Minnesota's $3 million exemption.
  4. File Form M706 by the deadline, even if probate is ongoing or values are estimated.
  5. Request a six-month extension before the due date if additional time is necessary.
  6. Pay any estimated tax owed at the time of filing or extension request.
  7. Consult a Minnesota estate tax attorney or CPA for estates near or above the exemption threshold.

Filing the Minnesota estate tax return on time during probate protects both the estate and the personal representative from unnecessary penalties. When in doubt, file early and amend later if values change.