Minnesota does not have estate tax portability. When the first spouse dies, any unused portion of their $3 million state estate tax exclusion disappears; it cannot be transferred to the surviving spouse. That’s the opposite of how federal estate tax works, and it’s the single most important thing for married couples in Minnesota to understand about state estate planning. To preserve both spouses’ exclusions, families have to use structures like credit shelter trusts or a state-only QTIP election.
Why the Missing Portability Matters
Portability, where it exists, lets a surviving spouse claim whatever portion of the deceased spouse’s exclusion went unused at death. If one spouse dies with a $1 million estate against a $3 million exclusion, a portability system would let the survivor add the remaining $2 million to their own exclusion. Married couples don’t lose tax benefits just because one spouse held fewer assets in their name.
Minnesota doesn’t work that way. The Department of Revenue treats each spouse’s estate as a separate unit with its own $3 million exclusion, and no mechanism exists to move unused exclusion between them.1Minnesota Department of Revenue. Analysis of S.F. 30 – Estate Tax Portability for Unused Exclusion Bills proposing state-level portability have been introduced in the Legislature, but as of 2026 none have been enacted.
The practical consequence: a couple with $6 million in combined assets, most of it titled in one spouse’s name, can end up paying Minnesota estate tax that better structuring would have avoided entirely. If the first spouse to die leaves everything outright to the survivor, that first $3 million exclusion is wasted. When the survivor later dies with $6 million in their own estate, only $3 million is sheltered and the rest is taxed.
How Federal Portability Works, and Why It Doesn’t Help in Minnesota
The federal system has allowed portability since 2011. The surviving spouse can add the deceased spouse’s unused exclusion, known as the DSUE, to their own federal exclusion.2Internal Revenue Service. Instructions for Form 706 For 2026, the federal exemption is $15 million per person after the One Big Beautiful Bill Act made the higher amount permanent and indexed to inflation.3Internal Revenue Service. Estate Tax A couple that properly elects federal portability can shield up to $30 million.
Federal portability isn’t automatic. The executor has to file IRS Form 706 within nine months of the date of death, even when the estate owes no federal tax.2Internal Revenue Service. Instructions for Form 706 A simplified late election under Revenue Procedure 2022-32 extends the window to five years, after which the option is gone.4Internal Revenue Service. Revenue Procedure 2022-32 Skipping Form 706 is one of the most common estate-administration mistakes, and it can cost a surviving spouse millions in future federal tax protection.
None of this touches Minnesota. A federal DSUE election does nothing for state estate tax. The $12 million gap between the federal exemption and the state exclusion is where nearly every Minnesota planning problem lives. A $5 million estate owes zero federal tax but faces Minnesota tax on $2 million above the state exclusion. Families that plan only against the federal number get blindsided.
The Minnesota $3 Million Exclusion and the Three-Year Gift Lookback
Minnesota’s exclusion has been $3 million per person for deaths in 2020 and later.5Minnesota Office of the Revisor of Statutes. Minnesota Code 291.016 – Minnesota Taxable Estate Everything above that is taxed under a bracket structure that runs from 13 percent to 16 percent.6Minnesota Office of the Revisor of Statutes. Minnesota Code 291.03 – Rates
One trap that catches families: Minnesota adds back taxable gifts made within three years of death. Someone who gave away $500,000 two years before dying and held $2.8 million in assets at death has a taxable estate of $3.3 million for state purposes, not $2.8 million.5Minnesota Office of the Revisor of Statutes. Minnesota Code 291.016 – Minnesota Taxable Estate Deathbed giving to duck below the threshold doesn’t work.
The taxable estate for Minnesota residents includes all real and personal property in the state plus intangible property wherever it’s held. Brokerage accounts custodied out of state still count.
Credit Shelter Trusts: The Main Workaround
Because Minnesota has no portability, credit shelter trusts do most of the work for married couples. The structure is sometimes called an A/B trust plan, with the B trust often referred to as a bypass trust or family trust.
At the first spouse’s death, assets are split. The B trust is funded with assets up to the Minnesota exclusion amount, currently $3 million. Those assets are permanently sheltered because they bypass the surviving spouse’s taxable estate. The A trust holds the rest and qualifies for the marital deduction, so no tax is due at the first death on that portion either.
The surviving spouse can still benefit from the B trust during their lifetime, typically receiving income and, under the trust terms, sometimes principal. But when the surviving spouse later dies, the B trust assets aren’t in their estate and aren’t taxed a second time. Funding the credit shelter trust up to the full $3 million at the first death is what keeps that first exclusion from vanishing. A couple that simply leaves everything to the survivor throws away one $3 million exclusion, which can cost heirs hundreds of thousands in state tax.
The State-Only QTIP Election
Minnesota gives executors a second tool that doesn’t exist in every state: the state-only Qualified Terminable Interest Property election. Under Minnesota Statute 291.03, Subdivision 1d, an executor can elect QTIP treatment for state estate tax purposes even if no QTIP election is made on the federal return.7Minnesota Office of the Revisor of Statutes. Minnesota Code 291.03 – Rates – Subdivision 1d Property passing to the surviving spouse qualifies for the state marital deduction, deferring Minnesota estate tax until the second death.
In practice: one spouse dies with a $5 million estate. The executor shelters $3 million with the state exclusion and elects QTIP treatment for the remaining $2 million, directing it into a trust that supports the surviving spouse for life. No Minnesota tax is due at the first death. The tradeoff is that the QTIP property gets added back into the survivor’s Minnesota taxable estate when they later die.5Minnesota Office of the Revisor of Statutes. Minnesota Code 291.016 – Minnesota Taxable Estate
The election requires strict compliance. The executor must identify the QTIP property on Form M706 and complete the required schedules. The surviving spouse must be entitled to all income from the property, paid at least annually, and no one else can hold a power to redirect the property during the survivor’s lifetime. These aren’t paperwork technicalities. Miss any of them and the election fails, triggering tax at the first death.
Farm and Small Business Property
Families with a farm or closely held business should know that Minnesota offers a separate deduction of up to $2 million on top of the $3 million exclusion for qualifying property, bringing the total possible shelter to $5 million.5Minnesota Office of the Revisor of Statutes. Minnesota Code 291.016 – Minnesota Taxable Estate The requirements are strict: material participation, ownership for at least three years before death, gross annual sales of $10 million or less for a business in the last taxable year, and continued use by qualified heirs after death. Sales outside the family within the required period can trigger a recapture tax.8Minnesota Office of the Revisor of Statutes. Minnesota Code 291.03 – Rates – Subdivision 9 This softens the absence of portability for farm and small business families but doesn’t replace it.
Filing Form M706 After a Death
Form M706 is due nine months after the date of death. Minnesota grants an automatic six-month extension to file, moving the deadline to 15 months after death. If the IRS grants a longer extension on the federal return, Minnesota matches it.9Minnesota Department of Revenue. 2025 Estate Tax Form M706 Instructions
An extension to file is not an extension to pay. Interest starts accruing on any unpaid tax nine months after death, regardless of any filing extension. Executors handling estates close to the $3 million line should get accurate asset valuations quickly, because the difference between a $2.9 million and a $3.1 million estate is the difference between no filing at all and a mandatory return with tax due.10Minnesota Department of Revenue. Estate Tax Filing Requirement If a credit shelter trust or state-only QTIP election is going to be made, the choices happen on this return, so a Minnesota-focused estate plan should be in place well before the nine-month clock starts.