IRS Rules for Joint Tenancy With Right of Survivorship

The IRS rules for joint tenancy with right of survivorship turn on two questions: were the co-owners married, and who paid for the property. For spouses who are both U.S. citizens, exactly half the value is pulled into the deceased spouse’s estate no matter who funded the purchase. For any other pair of co-owners, the IRS starts from the assumption that the deceased owner paid for the whole asset, and the survivor has to prove otherwise. That inclusion percentage then drives the estate tax bill, the income tax basis the survivor inherits, and in some cases the gift tax owed when the tenancy was first created.

The 50% Rule for Married Co-Owners

When spouses hold property as joint tenants with right of survivorship (JTWROS), the tax code treats it as a “qualified joint interest.” Half the fair market value on the date of death is included in the deceased spouse’s gross estate. It does not matter which spouse earned the money, made the down payment, or paid the mortgage.¹

That included half is almost always wiped out by the unlimited marital deduction, so no federal estate tax comes due. If a home is worth $1,200,000 when the first spouse dies, $600,000 is included in that spouse’s gross estate and the marital deduction absorbs it. The surviving spouse takes full ownership of the property without owing estate tax on the transfer.

The Consideration Furnished Rule for Everyone Else

Joint tenancies between a parent and child, siblings, unmarried partners, or any other non-spouse pairing follow a much harsher default. The IRS includes 100% of the property’s value in the deceased joint tenant’s gross estate. The burden shifts to the surviving co-owner to prove they contributed their own money toward the purchase price.¹

When the survivor can document their contribution, the included amount drops proportionally. Say a parent and adult child bought a rental property for $400,000, and the child contributed $100,000 of that price. If the parent dies when the property is worth $800,000, the child’s 25% contribution means only 75% of the current value, or $600,000, is included in the parent’s gross estate. If the parent funded the entire purchase, the full $800,000 goes in.

The money the survivor claims as their contribution must have “originally belonged to” the survivor and been “never received or acquired from the decedent.” Earnings the child made independently count. Cash the parent gave the child, which the child then put toward the purchase, does not. The IRS traces funds back to their source, which is why contemporaneous records matter from the day the tenancy is created.

How the Inclusion Percentage Sets the Survivor’s Basis

The percentage pulled into the estate controls one of the most valuable tax breaks in the code: the step-up in basis. Inherited property gets its cost basis reset to fair market value as of the date of death, which can wipe out decades of capital gains for income tax purposes when the survivor eventually sells.²

Spousal JTWROS Basis

Because exactly 50% of a qualified joint interest sits in the deceased spouse’s estate, only that half gets stepped up. The surviving spouse’s own half keeps its original cost basis.

Suppose the couple bought a property for $400,000, giving each spouse a $200,000 basis, and the property is worth $1,000,000 when the first spouse dies. The deceased spouse’s half steps up from $200,000 to $500,000. The survivor’s half stays at $200,000. The new total basis is $700,000. If the survivor sells immediately for $1,000,000, the taxable gain is $300,000 instead of $600,000.

Non-Spousal JTWROS Basis

Here the step-up can range anywhere from nothing to a complete reset. If the deceased co-owner funded the whole purchase, 100% is included in the estate and the survivor gets a full step-up to fair market value. All prior appreciation disappears for income tax purposes. If the survivor contributed half the purchase price, only 50% is included and only that half steps up. Pinning down the correct inclusion ratio is the executor’s job, because it sets the survivor’s basis for whenever the property is eventually sold.

Community Property Beats JTWROS on Basis

Married couples in community property states get a materially better deal on basis. Under a separate provision in the tax code, both halves of community property step up to fair market value when one spouse dies, including the surviving spouse’s half.²

Using the same numbers from above, if the couple held the property as community property instead of JTWROS, the surviving spouse’s new basis would be the full $1,000,000, not $700,000. That $300,000 difference flows straight through to lower capital gains tax on a sale. For this reason, planners in community property states sometimes advise against converting community property into joint tenancy form.

Alternate Valuation Date

If the estate files Form 706, the executor can elect to value all estate assets six months after the date of death instead of on the date of death. The election makes sense when values have dropped during that window, since the lower figure reduces the estate tax bill and sets the step-up at the lower number. It applies to the entire estate and cannot be used on an asset-by-asset basis.³

Gift Tax When the Joint Tenancy Is Created

Adding someone as a joint tenant on property you paid for can be a federal gift. The tax consequences depend on the asset and the relationship.

Real Estate

Titling real estate in JTWROS with a non-spouse is generally a completed gift of the fractional interest transferred, effective when the deed is recorded. A parent who buys a $500,000 house and adds an adult child to the deed has made a gift equal to the child’s fractional share of value. If the gift exceeds the annual exclusion ($19,000 per recipient for 2026), the donor must file IRS Form 709.⁴

Bank and Brokerage Accounts

Joint accounts work differently. Opening the account is usually an incomplete gift as long as the depositor keeps the power to withdraw everything. A completed gift happens only when the non-contributing co-owner pulls funds out for their own use. The withdrawn amount is the gift, counted in the year it leaves the account.

Transfers Between Spouses

The unlimited marital deduction eliminates gift tax on transfers between U.S. citizen spouses, regardless of amount. Setting up JTWROS with a citizen spouse has no gift tax consequence. If the spouse is not a U.S. citizen, that changes.

When the Surviving Spouse Isn’t a U.S. Citizen

The favorable spousal rules above assume both spouses are U.S. citizens. When the surviving spouse is not a citizen, two benefits disappear together: the automatic 50% inclusion rule does not apply, and the unlimited marital deduction is not available.⁵

Instead, the estate uses the same consideration-furnished tracing that governs non-spouse joint tenancies. The IRS presumes the deceased spouse funded the full purchase, and the executor must prove otherwise. Without the marital deduction to shelter the included amount, the estate owes real tax if the total gross estate exceeds the $15,000,000 exemption for 2026.¹

One workaround is a Qualified Domestic Trust, or QDOT. If the JTWROS property is transferred into a QDOT before the estate tax return is due, the marital deduction becomes available for that property. The trust must have at least one U.S. citizen trustee (or a domestic corporation serving as trustee), and no principal distributions can be made unless that trustee has the right to withhold the estate tax owed on the distribution.⁶ The QDOT election is made on the estate tax return and is irrevocable. If the surviving non-citizen spouse becomes a U.S. citizen before the estate tax return is filed and was continuously a U.S. resident after the death, the QDOT requirement falls away.⁵

Don’t Skip Form 706 Just Because the Estate Is Small

When one spouse dies and the estate is below the filing threshold, families often assume no Form 706 is needed. That assumption can cost millions in lost shelter. Portability lets a surviving spouse inherit the deceased spouse’s unused estate tax exemption, called the “deceased spousal unused exclusion” or DSUE. The IRS will not transfer the DSUE unless the executor files Form 706, even if no estate tax is due.⁷

With the 2026 exemption at $15,000,000, a married couple that elects portability can shelter up to $30,000,000 across both deaths.⁸ The standard filing deadline is nine months after the date of death, with a six-month extension available. Executors who missed the window solely to elect portability can file a late Form 706 up to five years after the decedent’s death.⁷

Federal Tax Liens on a Joint Tenant’s Interest

If one joint tenant owes back taxes, the IRS can place a federal tax lien on that person’s interest. The lien attaches only to the delinquent taxpayer’s share, but the IRS can force a judicial sale of the entire property under IRC § 7403, so long as the non-liable co-owner is compensated from the proceeds.⁹

If a buyer purchases the taxpayer’s interest at that sale, the joint tenancy typically converts to a tenancy in common under state law, destroying the right of survivorship. The survivorship feature also creates an unusual dynamic in most states: if the joint tenant with the tax debt dies first, the lien disappears because the debtor’s interest vanishes at death, and the surviving co-owner takes the property free of it. If the debtor outlives the other co-owner, the lien expands to cover the entire property. A small number of states are exceptions where the lien survives even after the debtor’s death.⁹

What the Surviving Owner Should Keep

For deaths in 2026, Form 706 is required if the gross estate (plus adjusted taxable gifts and any specific exemption amount) exceeds $15,000,000. JTWROS property goes into the gross estate at the percentage set by the spousal or consideration-furnished rules.⁸ Even when the estate falls below the threshold, the executor still has to calculate the inclusion ratio, because that number sets the survivor’s basis and the IRS can challenge it years later when the property is sold.

The survivor should hold onto:

The death certificate, which establishes the date that triggers the basis adjustment.
A qualified appraisal of the property as of the date of death, or of the alternate valuation date if that election was made. This locks in the fair market value used for the step-up.
For non-spousal joint tenancies, contribution records: bank statements, canceled checks, wire transfer records, or anything else showing who paid what toward the original purchase. Without them, the IRS defaults to 100% inclusion in the deceased tenant’s estate.
Form 706 itself if a return was filed, or the executor’s written determination of the inclusion ratio if no return was required. The inclusion percentage reported there controls the basis calculation going forward.

When the survivor eventually sells, the cost basis reported on the income tax return has to match the estate tax inclusion. A mismatch is one of the fastest ways to invite an audit or an unexpected capital gains bill.

1
Office of the Law Revision Counsel. 26 USC 2040 – Joint Interests
2
Office of the Law Revision Counsel. 26 USC 1014 – Basis of Property Acquired From a Decedent
3
Office of the Law Revision Counsel. 26 USC 2032 – Alternate Valuation
4
Internal Revenue Service. What’s New – Estate and Gift Tax
5
Office of the Law Revision Counsel. 26 USC 2056 – Bequests, Etc., to Surviving Spouse
6
Office of the Law Revision Counsel. 26 USC 2056A – Qualified Domestic Trust
7
Internal Revenue Service. Instructions for Form 706 (09/2025)
8
Internal Revenue Service. Frequently Asked Questions on Estate Taxes
9
Internal Revenue Service. 5.17.2 Federal Tax Liens