Blended Family Estate Planning: Using a 1031 and DSTs to Keep a Second Marriage Fair

The fairness problem is that one building cannot be split three ways without a sale

A blended-family estate plan usually has two goals that pull against each other: support the surviving spouse for life, and make sure the children from the first marriage eventually receive what their parent built. A single rental house or apartment building forces a choice, because whoever holds title controls it and decides when it is sold.

Selling and splitting cash solves the division but triggers the gain. An exchange solves it without the tax: section 1031 allows one relinquished property to be replaced by several, so one $1,500,000 building can become five or six separately titled DST interests. Each interest can then be assigned in the estate plan, retitled to a trust or left by will to a named beneficiary, subject to the sponsor's transfer rules.

The exchange itself must still be made by the same taxpayer who sold. If you add your new spouse to title on the replacement, read adding a spouse to replacement title first.

How title is held decides who gets the step-up, and blended families often get it wrong

Separate property you own alone is fully included in your estate, so section 1014 resets the whole basis at your death. That favors whoever inherits it, often a trust for children from the first marriage.

If you retitle a rental into joint tenancy with your new spouse, section 2040(b) includes only half the value in the first spouse's estate, regardless of who paid for it. Only that half gets a new basis, and the whole property passes to the survivor outside your will, which can disinherit your children by accident.

In a community property state, section 1014(b)(6) also resets the survivor's half when at least half of the community interest is included in the decedent's estate. That double step-up is valuable, but converting separate property to community property is a gift between spouses and a change in who ultimately controls it, so it belongs in a marital agreement, not a closing file.

A QTIP trust can hold the replacement property, if the trust lets the spouse demand productive assets

A qualified terminable interest property trust is the standard tool for this situation. Under section 2056(b)(7), property qualifies for the marital deduction if your spouse is entitled to all the income for life, payable at least annually, no one can appoint the property to anyone else during the spouse's life, and your executor elects QTIP treatment on the estate tax return. The remainder then goes to the beneficiaries you chose, such as your children.

At your spouse's later death, section 2044 includes the QTIP property in the spouse's estate, and section 1014(b)(10) gives it a second new basis. The deferred gain from your exchanges can be erased twice over a long marriage.

There is a catch for zero-income investments. Reg. section 20.2056(b)-5(f)(4), applied to QTIP trusts by Reg. section 20.2056(b)-7, says a power to keep unproductive property does not disqualify the income interest if the spouse can require the trustee to make it productive or convert it within a reasonable time. A zero cash flow DST or raw land inside a QTIP trust needs that clause, or it risks the deduction.

Worked model: one $1,500,000 rental, two families, and an exchange into separate interests

Hypothetical round numbers. A remarried owner holds a $1,500,000 apartment building as separate property, with a $400,000 adjusted basis and no mortgage. The owner wants the spouse supported for life and two children from the first marriage to receive the capital.

Selling for cash would realize $1,100,000 of gain. Exchanging defers all of it and replaces the building with, for example, five DST interests of $300,000 each, run your own numbers with your CPA. The estate plan can then direct three interests into a QTIP trust for the spouse, with remainder to the children, and leave two outright to the children, giving each family something it controls without waiting for one building to sell.

• At the owner's death, section 1014 resets basis on all five interests to their date-of-death value, because separate property is fully included.
• The QTIP election on the three interests in trust defers estate tax on them until the spouse's death, when they are included again and stepped up again.
• The two interests left to the children use part of the owner's own exclusion, which is $15,000,000 in 2026 under Rev. Proc. 2025-32.
• If the owner's exclusion goes unused, the executor can pass the remainder to the spouse only by filing an estate tax return and making the portability election under section 2010(c)(5)(A).

Put the exchange and the estate documents in the same plan, and sign them in order

The order matters. Decide the ownership of each replacement interest before you close, because the identification and the purchase documents name the buyer. The exchange must close in the name of the taxpayer who sold, but replacement interests bought in your revocable trust's name are generally treated as yours, since you are taxed as owner of a revocable trust; see DST property held in an LLC or trust.

Then align the documents: the will or trust that directs specific DST interests, the QTIP terms with a productive-property clause, beneficiary instructions for the sponsor's transfer forms, and a marital agreement if community property is involved. Transferring DSTs to heirs and trusts and DSTs in estate planning cover the mechanics on the sponsor's side.

Fairness also means accepting the DST trade-offs: the interests are illiquid, distributions are not guaranteed, and neither the spouse nor the children can direct the property. A family that wants an asset someone can run should keep at least part in direct ownership.