Portability Election Calculator
Should the first spouse's estate file a return just to carry the unused exclusion to the survivor? Every piece below can be linked to, so it opens in a window on your reader's screen, current as of the record. No form to fill in.
2026 law · Reviewed September 6, 2026 · The full page, with methodology and sources · the terms · All tools
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What the first spouse left to others and the survivor's projected estate in; the unused exclusion, the survivor's exclusion each way, the federal tax each way, and the Illinois tax out. In a frame it carries no cookies, no tracking, and a visible link back to the methodology. Your site has to allow frames; most do. The link that opens it in a small window is on the professionals page.
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- In plain words.
- Each person can leave a large amount free of federal estate tax. When the first spouse dies and leaves everything to the survivor, none of that allowance is used. The law lets the survivor add it to their own, doubling what they can leave, but only if the first estate files an estate tax return and asks for it, even when no tax is due. This tool takes what the first spouse left to others and the survivor's expected estate, and shows the federal tax with and without the election.
- Why it matters.
- The filing happens when the estate looks too small to bother, and the value shows up years later when the survivor's estate has grown. Skip it and the allowance is gone. Illinois has no version of this, which is why Illinois couples still plan differently.
- An example.
- The first spouse leaves everything to the survivor. If the survivor later dies with $20 million, the federal tax is about $2 million without the election and nothing with it. The Illinois tax is the same either way.
- Where it stops.
- It uses today's exclusion, which the law can change, and treats the survivor's estate as taxed at the top rate above the allowance. Lifetime gifts, the exact return due date, and whether a trust at the first death would serve better are the attorney's questions.
The facts
Six quotable sentences on portability, 2026 figures.
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- Each person can leave $15 million free of federal estate tax in 2026. Whatever a first spouse does not use, because everything went to the survivor or to charity, can be added to the survivor's own exclusion (§ 2010(c)(2), (4)), but only if the first estate files an estate tax return and elects it (§ 2010(c)(5)).
- Without the election, the unused amount is lost when the survivor dies with more than their own exclusion. With it, a couple can shelter $30 million in all, at 40% on the excess.
- Example: the first spouse leaves everything to the survivor, using none of the exclusion. If the survivor later dies with $20 million, the federal tax is $2,000,000 without the election and $0 with it.
- The return is due nine months after the death, but an estate not otherwise required to file may make the election on a return filed within 5 years (Rev. Proc. 2022-32). After that, the amount is gone.
- Illinois has no portability: its $4 million exclusion is per person and unused amounts are lost at the first death, which is why Illinois couples still use trusts at the first death to preserve the first spouse's exclusion.
- The election costs a return, an appraisal, and a fee, at a time when the estate seems too small to matter; the survivor's estate grows, the law can change, and the filing is the only way to keep the option.
What the election is worth
Nothing to the survivor at the first death; everything turns on how large the survivor's estate becomes.
The button shows exactly what your reader sees when they click the link. Paste the link where a link goes; it opens this table in a small window, always current as of the record, with the attribution and a link to the full page. Nothing to copy out, nothing to update later.
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| Survivor's estate | Federal tax, no election | Federal tax, with election | Saved | Illinois tax either way |
|---|---|---|---|---|
| $10 million | $0 | $0 | $0 | $926,923 |
| $15 million | $0 | $0 | $0 | $1,609,310 |
| $20 million | $2,000,000 | $0 | $2,000,000 | $2,298,965 |
| $30 million | $6,000,000 | $0 | $6,000,000 | $3,678,276 |
Cite and link.
The clean address, a citation generated from the record so it can never carry a stale review date, and an address for every section so you can point a reader at the exact table or method.
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- Link
- https://consideratecapital.com/tools/portability-election-calculator
- Citation
- Considerate Capital, "Portability Election Calculator," reviewed September 6, 2026, https://consideratecapital.com/tools/portability-election-calculator.
Link to a section
- The calculator https://consideratecapital.com/tools/portability-election-calculator#calculator
- The facts https://consideratecapital.com/tools/portability-election-calculator#facts
- What the election is worth https://consideratecapital.com/tools/portability-election-calculator#key-numbers
- How portability works https://consideratecapital.com/tools/portability-election-calculator#how-it-works
- Methodology https://consideratecapital.com/tools/portability-election-calculator#methodology
- Sources https://consideratecapital.com/tools/portability-election-calculator#sources
- Revision history https://consideratecapital.com/tools/portability-election-calculator#revision-history
Everything here reads from one reviewed record, so a copied piece carries its year and its review date. When the law moves, the embed updates by itself; a copied table or chart keeps the year in its caption. Corrections are welcome through the contact page.