Updated July 28, 2026. Quick answer: No. Washington has no state income tax, so converting to a Roth costs you nothing at the state level. Only the federal bill applies.
Why a conversion is a different question from a withdrawal
Almost every state summary answers “how does Washington tax retirement income?” That is a question about distributions. A Roth conversion is not a distribution in the ordinary sense — it is a voluntary election to recognise income now in exchange for tax-free growth later. Whether a state’s retirement exclusion reaches that election is a separate question, and it is the one that decides your bill.
This is the simplest case on the map. Washington levies no tax on ordinary income, so the entire question of whether a retirement exclusion covers a conversion never arises. Your conversion is a federal-only event here.
The planning consequence is the opposite of what people expect: because the state adds nothing, the timing question in Washington is purely federal — bracket, IRMAA, and the tax you pay from outside the account.
What Washington does with the converted amount
State income tax: none on wages or retirement income (state levies a 7% excise on long-term capital gains above an inflation-adjusted deduction (~$270k+), plus a 2.9% surtax on gains over $1M enacted 2025 – retirement-account gains and distributions are exempt from it)
How Washington treats IRA and plan income: Not taxed (no personal income tax; capital gains excise explicitly exempts assets held in retirement accounts).
| Conversion | State tax in Washington |
|---|---|
| $50,000 | $0 |
| $100,000 | $0 |
| $250,000 | $0 |
What to ask a preparer about Washington
Nothing to ask at the state level. Spend the question on federal timing.
Converting around a move
Converting after establishing residency in Washington is the whole play. People moving here from a taxing state sometimes convert before the move and pay a state bill they could have avoided entirely by waiting.
Four separate taxes change when you move, not one: income tax on withdrawals, treatment of Social Security, estate tax, and inheritance tax. A state that looks good on conversions can be worse on the other three.
The state bill is the smaller half
Whatever Washington does, the conversion is federal ordinary income first. The federal bracket you land in, and whether the conversion pushes you over an IRMAA threshold two years later, will usually move more money than the state line does. The state answer tells you whether to convert here; the federal answer tells you how much to convert at once.
Paying the tax from outside the account matters more than either. Using converted dollars to pay the bill shrinks the balance that was the entire point of converting.
Sources
Authority: RCW 82.87 (capital gains excise; retirement account exemption at RCW 82.87.050); RCW 83.100.040; RCW 83.100.020; Laws of 2025, ch. 418 (ESSB 5813).
Compiled from state statutes, session laws and revenue-department publications and adversarially verified in July 2026. Dataset confidence for Washington: high.
This page states what the cited authority says. It is not tax advice, and a conversion large enough to matter is worth putting in front of a preparer who can see your whole return.