The unlimited marital deduction is a provision in the United States Federal Estate and Gift Tax Law that allows an individual to transfer an unrestricted amount of assets to his or her spouse at any time, including at the death of the transferor, free from tax. The unlimited marital deduction is considered an estate preservation tool because assets can be distributed to surviving spouses without incurring estate or gift tax liabilities.

Breaking Down Unlimited Marital Deduction

The unlimited marital deduction is an estate tax provision that went into effect in 1982. The provision eliminated both the federal estate and gift tax on transfers of property between spouses, in effect, treating them as one economic unit. The deduction was adopted by Congress to redress the problem of estates being pushed into higher tax brackets by inflation. Because the estate tax, like the income tax, is progressive, estates that grow with inflation are hit with higher tax rates.

With the unlimited marital deduction, the amount of property that can be transferred between spouses is unlimited, meaning that a spouse can transfer all of his or her property to the other spouse, during lifetime or at death, without incurring any federal estate or gift tax liabilities on this first transfer. The transfer is made possible through an unlimited deduction from estate and gift tax that postpones the transfers taxes on the property inherited from each other until the second spouse’s death. In other words, the unlimited marital deduction allows married couples to delay the payment of estate taxes upon the death of the first spouse because after the surviving spouse dies, all assets in the estate over the applicable exclusion amount will be included in the survivor’s taxable estate.

Any asset that is transferred to a surviving spouse can be included in the spouse's taxable estate unless it is spent or gifted during the surviving spouse's lifetime. Alternatively, if the surviving spouse remarries, the unlimited marital deduction may allow the assets to pass to the new spouse without the application of estate and/or gift taxes. In some situations, fewer taxes will be paid by using other estate planning methods such as using exemptions or trusts.

The unlimited marital deduction applies only to surviving spouses that are United States citizens. A Qualified Domestic Trust (or QDOT) may be obtained to provide unlimited marital deductions for non-qualified spouses. A bequest through a QDOT defers estate tax until the principal is distributed by the trustee, a U.S. citizen, or corporation who also withholds the estate tax. Income on principal distributed to the surviving spouse is taxed as individual income. After the surviving spouse becomes a U.S. citizen, principal remaining in a QDOT may then be distributed without further tax.