Washington's Estate Tax Just Changed Twice: What the 2025–2026 Whiplash Means for Your Plan

By Chad Foster, Family Law Attorney · Updated July 16, 2026

If you read an estate tax article written before this spring, there's a real chance it's already wrong. Washington has rewritten its estate tax twice in under two years, and the single most important rule, the one that decides which version of the law applies to you, is also the easiest to overlook.

The Headline Rule: Date of Death Controls

Washington's estate tax is governed by the decedent's date of death. Whatever the law says on the day a person dies is the law that applies to their estate. It does not matter when the will was signed, when the trust was funded, or when the return is filed. The date of death freezes the rules in place.

That principle is ordinarily a quiet technicality. Right now it is the whole story, because Washington has had three different estate tax regimes inside a 24-month window. An estate worth exactly the same amount could owe dramatically different tax depending on whether the person died in June 2025, in early 2026, or in July 2026.

This is also why so much of what you'll find online is unreliable, and we'll be candid: until recently, two articles on this very site reflected the older rules. We've corrected them. Most firms haven't gotten there yet, which is part of why we're publishing this now. When you research Washington estate tax, check the publication date on everything, including the pages that sound authoritative.

The Three Regimes at a Glance

The graduated rate schedule and exclusion amount both live in RCW 83.100.040, the statute the legislature amended in 2025 and then amended again in 2026. Here is how the three windows line up.

Date of death	Exemption (exclusion amount)	Top marginal rate	Governing law
Before July 1, 2025	$2.193 million	20% on amounts over $9M	Pre-2025 RCW 83.100.040
July 1, 2025 – June 30, 2026	$3 million (CPI-adjusted to roughly $3.076M for 2026 deaths)	35% on amounts over $9M	ESSB 5813
On or after July 1, 2026	$3 million, effectively frozen	20% on amounts over $9M	ESB 6347 (signed March 24, 2026)

A few points deserve emphasis. ESSB 5813 raised the exemption from $2.193 million to $3 million and re-tied it to inflation, but it also pushed the top rate up to 35%, which at the time made Washington's top estate tax rate the highest in the nation. The increase applied to decedents dying on or after July 1, 2025.

Then the legislature reversed course. ESB 6347, signed by Governor Ferguson on March 24, 2026, restores the pre-2025 graduated schedule with a 20% top rate for deaths on or after July 1, 2026, while keeping the $3 million exemption. There is a subtle catch worth understanding: the 2026 law reinstates the same broken inflation-index reference that froze the old exemption for years. In practical terms, the $3 million figure is once again effectively static rather than reliably growing with inflation.

That subtlety creates the strange middle window. A person who dies in the first half of 2026 falls under ESSB 5813, which means a CPI-adjusted exemption near $3.076 million but the full 35% top rate. For larger estates, the difference between dying in June 2026 and dying in July 2026 can be substantial. On a $10 million taxable estate, the rate rollback alone can mean roughly $200,000 in tax.

Why the Federal Exemption Doesn't Save You

Many people hear that Congress made the federal estate tax exemption permanent at $15 million and conclude they're in the clear. For federal purposes, most families are. The One Big Beautiful Bill Act set the federal basic exclusion amount at $15 million per individual ($30 million for married couples) beginning January 1, 2026, indexed for inflation.

Washington, however, runs its own estate tax entirely independent of the federal system. The state exemption is $3 million, not $15 million. That leaves a $12 million gap where the federal government takes nothing but Washington still taxes the estate.

This is precisely the band where a great many King and Snohomish County homeowners live. A paid-off house in a desirable neighborhood, a retirement account, a life insurance policy, and some savings add up quickly. A family that never thought of itself as wealthy can land well above $3 million on paper while remaining nowhere near the federal threshold. Being "fine federally" tells you almost nothing about your Washington exposure.

What This Actually Changes About Your Plan

The rate rollback is good news for larger estates, but it does shift some of the math that planners have relied on.

For married couples, the credit shelter trust (sometimes called a bypass or family trust) remains a workhorse because Washington does not offer portability of the state exemption the way the federal system does. Without planning, the exemption of the first spouse to die can simply evaporate, leaving the survivor's estate to absorb everything above a single $3 million exclusion. A properly structured credit shelter trust preserves both spouses' exemptions, potentially sheltering up to $6 million from Washington estate tax. The rate change doesn't alter that core logic, but it does change the cost of getting it wrong: at a 20% top rate rather than 35%, the penalty for a wasted exemption is smaller in absolute dollars, though still very real. Our wills and trusts page covers these structures in more depth.

The frozen exemption is the quieter long-term concern. Because ESB 6347 effectively stops the $3 million figure from rising with inflation, ordinary asset growth will slowly pull more estates over the line each year. An estate comfortably under the threshold today can drift above it through nothing more than home appreciation and market returns. The threshold standing still while the world inflates around it is a feature of the new law, not an accident, and it means "I'm under $3 million" is a conclusion with a shelf life.

One habit worth adopting regardless of where your estate sits: verify the current numbers directly with the Washington Department of Revenue rather than relying on secondhand summaries. As this two-year saga shows, the figures move, and the DOR is the authoritative source for the exclusion amount, rate tables, and filing thresholds in effect on any given date. Building that verification step into any review is the simplest defense against acting on stale information.

Who Should Review Their Plan Now

Three groups have the most at stake in this transition.

First, anyone with an estate roughly between $3 million and $9 million. You're above the Washington exemption but below the top bracket, which is exactly the range where exemption planning and trust structure make the largest proportional difference.

Second, anyone whose plan was drafted under the old $2.193 million assumption. Documents built around that lower figure may not take full advantage of the higher exemption, and formulas calibrated to the old number can behave unpredictably now.

Third, and most urgently, anyone whose will or trust contains a formula clause tied to "the exemption amount" or "the applicable exclusion." These formulas were designed to flex automatically as the law changed, but a provision that worked sensibly at $2.193 million can produce lopsided or unintended results when the underlying number jumps to $3 million, or when it points ambiguously between the state and federal figures. Formula clauses are powerful precisely because they're automatic, which means a poorly aimed one can misfire without anyone noticing until it's too late.

If you're settling the estate of someone who died during the transition window, the date of death is the first fact to pin down, because it determines which of the three regimes governs everything that follows. Our probate and estate administration page covers what comes next.

Washington's estate tax has changed twice in two years, and it may not be finished. If your plan predates these shifts, or if you're unsure which set of rules applies to your family, this is a good moment to have it reviewed against the law as it actually stands today. The Law Office of Chad Foster helps Snohomish County families make sense of exactly these questions. Reach out whenever you're ready to take a fresh look.