Late estate-tax portability election allowed for a surviving spouse

Plain-English summary

A married person died leaving part of their federal estate-tax exemption unused. That leftover amount (the deceased spousal unused exclusion, or DSUE) can pass to the surviving spouse, but only if the estate makes a "portability" election on a timely estate tax return. This estate was small enough that it did not have to file a return, so no return was filed and the election was missed. After finding the error, the estate asked the IRS for more time. Because the estate was not required to file, the election deadline is set by regulation, letting the IRS grant relief under Treas. Reg. § 301.9100-3 if the estate acted reasonably and in good faith and relief does not prejudice the government. The IRS granted a 120-day extension to file Form 706 and elect portability. The extension is void if the estate turns out to have been required to file anyway, and the IRS expresses no opinion on the actual DSUE amount, which remains subject to audit.

Ruling snapshot

• Question: May a small estate that was not required to file an estate tax return get more time to make a late portability election?
• Outcome: approved (120-day extension granted)
• Key authorities: IRC § 2010(c)(5)(A); IRC §§ 2001, 6018(a); Treas. Reg. §§ 20.2010-2, 20.2010-3; Treas. Reg. §§ 301.9100-1 and 301.9100-3

Full text (IRS public release)

 Internal Revenue Service                                      Department of the Treasury
                                                               Washington, DC 20224

 Number: 202609001                                             Third Party Communication: None
 Release Date: 2/27/2026                                       Date of Communication: Not Applicable
 Index Number: 9100.35-00, 2010.04-00
                                                               Person To Contact:
 ------------------------------------                          -------------------------- ID No. -----------------
 ---------------------------                                   -----------------------------------------------------
 ----------------------------                                  Telephone Number:
                                                               --------------------
                                                               Refer Reply To:
                                                               CC:PT&E:B04
 ---------------------------------------------------------     PLR-109154-25
                                                               Date:
                                                               November 18, 2025




Legend

Decedent         =        ------------------------------------------------------
Spouse           =        -------------------------------------------------
Date             =        ------------------

Dear --------------:

        This letter responds to a letter dated April 7, 2025, and subsequent
correspondence, submitted on behalf of Decedent’s estate, requesting an extension of
time pursuant to § 301.9100-3 of the Procedure and Administration Regulations to make
an election. Decedent’s estate is requesting to make an election under § 2010(c)(5)(A)
of the Internal Revenue Code (a “portability” election) to allow a decedent’s surviving
spouse to take into account that decedent’s deceased spousal unused exclusion
(DSUE) amount.

        The information submitted for consideration is summarized below.

       Decedent died on Date, survived by Spouse. It is represented that based on the
value of Decedent’s gross estate and taking into account any taxable gifts, Decedent’s
estate is not required under § 6018(a) to file an estate tax return (Form 706, United
States Estate (and Generation-Skipping Transfer) Tax Return). It is further represented
that there is an unused portion of Decedent’s applicable exclusion amount and that a
portability election is required to allow Spouse to take into account that amount (the
“DSUE” amount). A portability election is made upon the timely filing of a complete and
properly prepared estate tax return, unless the requirements for opting out are satisfied.
See § 20.2010-2(a)(2) of the Estate Tax Regulations. For various reasons, an estate
tax return was not timely filed and a portability election was not made. After discovery
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of this error, Decedent’s estate submitted this request for an extension of time under
§ 301.9100-3 to make a portability election.

LAW AND ANALYSIS

     Section 2001(a) imposes a tax on the transfer of the taxable estate of every
decedent who is a citizen or resident of the United States.

      Section 2010(a) provides that a credit of the applicable credit amount shall be
allowed to the estate of every decedent against the tax imposed by § 2001.

       Section 2010(c)(1) provides that the applicable credit amount is the amount of
the tentative tax that would be determined under § 2001(c) if the amount with respect to
which such tentative tax is to be computed were equal to the applicable exclusion
amount.

      On December 17, 2010, Congress amended § 2010(c), effective for estates of
decedents dying and gifts made after December 31, 2010, to allow portability of a
decedent’s unused applicable exclusion amount between spouses. Tax Relief,
Unemployment Insurance Reauthorization, and Job Creation Act of 2010,
Pub. L. No. 111-312, § 303, 124 Stat. 3296, 3302 (2010).

      Section 2010(c)(2) provides that the applicable exclusion amount is the sum of
the basic exclusion amount, and, in the case of a surviving spouse, the DSUE amount.

      Section 2010(c)(3) provides the basic exclusion amount available to the estate of
every decedent, an amount to be adjusted for inflation annually after calendar year
2011.

        Section 2010(c)(4) defines the DSUE amount to mean the lesser of (A) the basic
exclusion amount, or (B) the excess of -- (i) the applicable exclusion amount of the last
deceased spouse of the surviving spouse, over (ii) the amount with respect to which the
tentative tax is determined under § 2001(b)(1) on the estate of such deceased spouse.

        Section 2010(c)(5)(A) provides that a DSUE amount may not be taken into
account by a surviving spouse under § 2010(c)(2) unless the executor of the estate of
the deceased spouse files an estate tax return on which such amount is computed and
makes an election on such return that such amount may be so taken into account. The
election, once made, shall be irrevocable. No election may be made if such return is
filed after the time prescribed by law (including extensions) for filing such return.

       Section 20.2010-2(a)(1) provides that the due date of an estate tax return
required to elect portability is nine months after the decedent’s date of death or the last
day of the period covered by an extension (if an extension of time for filing has been
obtained). Under § 20.2010-2(a)(1), an extension of time under § 301.9100-3 to make a
PLR-109154-25                                  3

portability election may be granted in the case of an estate that is not required to file an
estate tax return under § 6018(a), as determined solely based on the value of the gross
estate and any adjusted taxable gifts (and without regard to § 20.2010-2(a)).

       Under § 301.9100-1(c), the Commissioner has discretion to grant a reasonable
extension of time under the rules set forth in §§ 301.9100-2 and 301.9100-3 to make a
regulatory election, or a statutory election (but no more than six months except in the
case of a taxpayer who is abroad), under all subtitles of the Internal Revenue Code
except subtitles E, G, H, and I.

        Section 301.9100-3 provides the standards the Commissioner will use to
determine whether to grant an extension of time to make an election whose due date is
prescribed by a regulation (and not expressly provided by statute). Requests for relief
under § 301.9100-3 will be granted when the taxpayer provides evidence to establish to
the satisfaction of the Commissioner that the taxpayer acted reasonably and in good
faith, and that granting relief will not prejudice the interests of the government.

       In this case, based on the representation as to the value of the gross estate and
any adjusted taxable gifts, the time for filing the portability election is fixed by the
regulations. Therefore, the Commissioner has discretionary authority under
§ 301.9100-3 to grant an extension of time for Decedent’s estate to elect portability,
provided Decedent’s estate establishes it acted reasonably and in good faith, the
requirements of §§ 301.9100-1 and 301.9100-3 are satisfied, and granting relief will not
prejudice the interests of the government.

        Information, affidavits, and representations submitted on behalf of Decedent’s
estate explain the circumstances that resulted in the failure to timely file a valid election.
Based solely on the information submitted and the representations made, we conclude
that the requirements of §§ 301.9100-1 and 301.9100-3 have been satisfied. Therefore,
we grant an extension of time of 120 days from the date of this letter in which to make
the portability election. The election should be made by filing a complete and properly
prepared Form 706 and a copy of this letter, within 120 days from the date of this letter,
with the Kansas City Service Center, at the following address: Department of the
Treasury, Internal Revenue Service Center, Kansas City, MO 64999. For purposes of
electing portability, a Form 706 filed by Decedent’s estate within 120 days from the date
of this letter will be considered to be timely filed.

        If it is later determined that, based on the value of the gross estate and taking
into account any taxable gifts, Decedent’s estate is required to file an estate tax return
pursuant to § 6018(a), the Commissioner is without authority under § 301.9100-3 to
grant an extension of time to elect portability and the grant of the extension referred to
in this letter is deemed null and void. See § 20.2010-2(a)(1).

      We neither express nor imply any opinion concerning the tax consequences of
any aspect of any transaction or item discussed or referenced in this letter. In
PLR-109154-25                                4

particular, we express no opinion as to the DSUE amount to be potentially taken into
account by Spouse. Any claimed DSUE amount will be included in the applicable
exclusion amount of Spouse only to the extent that Spouse can substantiate such
amount and will be subject to determination by the Director’s office upon audit of
relevant Federal gift or estate tax returns. See § 20.2010-3(c)(1) and (d).

      The rulings contained in this letter are based upon information and
representations submitted by the Taxpayer and accompanied by a penalty of perjury
statement executed by an appropriate party. While this office has not verified any of the
material submitted in support of the request for rulings, it is subject to verification on
examination.

      This ruling is directed only to the Taxpayer requesting it. Section 6110(k)(3)
provides that it may not be used or cited as precedent.

      In accordance with the Power of Attorney on file with this office, we have sent a
copy of this letter to your authorized representatives.


                                         Sincerely,

                                         Associate Chief Counsel
                                         Passthroughs, Trusts, and Estates



                                         Leslie H. Finlow
                                         ______________________________
                                 By:     [Leslie H. Finlow]
                                         Senior Technician Reviewer, Branch 4
                                         Office of the Associate Chief Counsel
                                         (Passthroughs, Trusts, and Estates)




 Enclosure:
       Copy for § 6110 purposes
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