Updated October 18, 2026. Quick answer: Part VI is where an estate elects portability, the transfer of a decedent’s unused exclusion to the surviving spouse. Section A opts out, Section B asks about a QDOT, Section C figures the DSUE amount that passes to the surviving spouse, and Section D records DSUE the decedent received from earlier spouses.
What portability is
“Section 2010(c)(4) authorizes estates of decedents dying after December 31, 2010, to elect to transfer any unused exclusion to the surviving spouse.” “The amount received by the surviving spouse is called the deceased spousal unused exclusion (DSUE) amount.” The filing rule at the start of the instructions lists, among the estates that must file, one “Whose executor elects to transfer the deceased spousal unused exclusion (DSUE) amount to the surviving spouse, regardless of the size of the decedent’s gross estate.” The return is explained on the Form 706 page.
Making the election
The form says “A decedent with a surviving spouse elects portability of the DSUE amount, if any, by completing and timely filing this return.” “No further action is required to elect portability of the DSUE amount to allow the surviving spouse to use the decedent’s DSUE amount.”
The instructions add “A timely filed and complete Form 706 is required to elect portability of the DSUE amount to a surviving spouse.” “The filing requirement applies to all estates of decedents choosing to elect portability of the DSUE amount, regardless of the size of the estate.” “A timely filed return is one that is filed on or before the due date of the return, including extensions.” Due dates are on the Form 706 due date and extension page.
“A portability election is irrevocable, unless an adjustment or amendment to the election is made on a subsequent return filed on or before the due date.” One limit: “the executor of an estate of a nonresident decedent who was not a citizen of the United States at the time of death cannot make a portability election.”
Section A: opting out
“If an estate files a Form 706 but does not wish to make the portability election, the executor can opt out of the portability election by checking the box indicated in Section A of this Part.” “If no return is required under section 6018(a), not filing Form 706 will avoid making the election.” The form caption adds “Check only if the estate opts NOT to elect portability of the DSUE amount.”
Section B: QDOT
The form asks “Are any assets of the estate being transferred to a QDOT?” The instructions say “Complete Section B if any assets of the estate are being transferred to a QDOT”. Marital transfers are covered on the Schedule M page.
Section C: the DSUE amount that passes to the spouse
“Complete Section C only if electing portability of the DSUE amount to the surviving spouse.” “On line 1, enter the decedent’s applicable exclusion amount from Part II, line 9d.” “On line 2, enter the value of the cumulative lifetime gifts on which gift tax was paid or payable, from the Line 7 Worksheet, Part B, line 6.” “On line 9, enter the basic exclusion amount from Part II, line 9a.” “On line 10, enter the smaller of line 8 or line 9. This will be the DSUE amount available to the surviving spouse.”
In summary: “The DSUE amount is the lesser of (a) the basic exclusion amount in effect on the date of death of the decedent whose DSUE is being figured, or (b) the decedent’s applicable exclusion amount less the amount on Part II, line 5 on the Form 706 for the estate of the decedent.” The line captions are on the form, such as “Enter the amount from Part II, line 5”.
Section D: DSUE received from earlier spouses
“Complete Section D if the decedent was a surviving spouse who received a DSUE amount from one or more predeceased spouses.” “On line 4, add line 3 and line 1, column D, if any, to determine the decedent’s total DSUE amount.” The form says the total goes “Enter here and on Part II, line 9b”. That line is covered in Part II lines 9 to 12.
The last deceased spouse is defined this way: “The last deceased spouse is the most recently deceased person who was married to the surviving spouse at the time of that person’s death.”
Where the numbers come from
The Section C inputs come from other parts of the return: line 9d and line 9a from Part II lines 9 to 12, line 5 from Part II lines 1 to 8, and the lifetime gift figure from the Line 7 Worksheet. Section D comes from the predeceased spouses’ returns.
Where it goes next
The Section C result is the amount available to the surviving spouse. Section D, line 4 flows back to Part II, line 9b, the credit step covered in Part II lines 9 to 12. A surviving spouse can also read the planning side on the estate tax exemption page.
Edition and line numbers
This page reads the Form 706 revision dated August 2025 and the Instructions for Form 706 revision dated July 2026. Those are the current files irs.gov served on 2026-10-18, byte-identical to the archived copies. The instructions state “For decedents dying after December 31, 2025.” The form itself says “To be filed for decedents dying after December 31, 2024.” Check the revision date printed on your Form 706 and the instruction edition for the year of death, and use the line numbers on that revision, because a different revision can number or word its lines differently.
Common mistakes
- Assuming a small estate need not file to elect portability. The instructions say “The filing requirement applies to all estates of decedents choosing to elect portability of the DSUE amount, regardless of the size of the estate.”
- Filing after the due date. The instructions say “A timely filed return is one that is filed on or before the due date of the return, including extensions.”
- Completing Sections B and C after opting out. The instructions say “Do not complete Section B or C.”
Related: Form 706, Form 706 due date and extension, estate tax exemption, and estate planning.
Find the right next step for your situation
About how much do you have invested? Pick the range that fits; your next step appears immediately below.
advisor help with estate tax portability
For U.S. investors with $250,000 or more in investable assets. WiserAdvisor is an independent service matching you with 2 to 3 vetted advisers. Its form asks for your ZIP code and answers to a few questions; a match is not guaranteed.
Free to request, with no obligation to hire. By submitting, you consent to calls, texts and emails from WiserAdvisor and up to three advisers. Advisers pay for introductions.
Clear Money Guide may earn a referral payment for a qualifying completed form. An introduction is not a Clear Money Guide recommendation.
Opens on WiserAdvisor’s site in a new tab.
surviving spouse estate planning options
Price the destination before you decide. The matching service below introduces you to advisers who pay to meet you.
Before you start, what actually happens. The form is run by Kapitalwise, our advisor-matching partner. Kapitalwise sends your details to advisers who pay for the introduction, so expect calls and texts. Clear Money Guide may earn a referral payment for a qualifying submitted form, whether or not you ever hire anyone. This is free to you and there is no obligation to hire anyone.
The Kapitalwise form opens here; you stay on this page.
What happens when you press the button
It asks about nine questions: age, investable assets, location; then your name, email and phone number, and verifies the phone by text. Nothing loads and nothing reaches Kapitalwise until you press the button.
Prefer flat-fee or hourly pricing instead? Compare ranges here.
Answer againSources
- Instructions for Form 706 (Rev. July 2026): https://www.irs.gov/pub/irs-pdf/i706.pdf
- Form 706 (Rev. August 2025), United States Estate (and Generation-Skipping Transfer) Tax Return: https://www.irs.gov/pub/irs-pdf/f706.pdf
Read from the IRS documents linked above on October 18, 2026. General information, not tax advice. Your own facts decide the outcome, and a preparer, the account provider or the IRS is the right place to confirm anything consequential.