Washington millionaires tax: income mix of top filers, floor amendment votes, worked household examples and payer projection

What this dataset measures

Built to show, from official records, which kinds of income and households ESSB 6346 reaches beyond people who earn $1 million a year in wages: married couples sharing one deduction, retirees and heirs with one-time distributions, households whose capital gains push wages over the line, and future households as the threshold loses value. The amendment votes record which of these the Legislature considered and rejected.

Geography

Washington, United States

Unit of observation

Varies by table: federal individual income tax returns by AGI class and year; floor amendments; illustrative households; tax years

Update cadence

Irregular; update when IRS releases tax year 2023 state data or the law changes

Curator

FactHub Research Team

Curated data tables

These related tables form this versioned dataset release. Each table has its own downloadable file and field definitions.

Washington federal returns by AGI class: income types and joint returns, 2019-2022

All returns and the two top AGI classes from the IRS state file for Washington.

Unit of observation: Tax year and AGI class

View this table

irs_wa_top_returns.csv text/csv · 2.1 KB (2,103 bytes)

17 field definitions

Field	Type	Meaning	Units	Value type
taxYear	integer	Federal tax year	—	observed
agiClass	string	IRS size-of-AGI class: All returns, $500,000 under $1,000,000, or $1,000,000 or more	—	observed
returns	integer	Number of returns (N1)	returns	observed
jointReturns	integer	Number of joint returns (MARS2)	returns	observed
agiDollars	number	Adjusted gross income (A00100)	US dollars	observed
wageReturns	integer	Returns with salaries and wages (N00200)	returns	observed
wagesDollars	number	Salaries and wages (A00200)	US dollars	observed
pensionReturns	integer	Returns with taxable pensions and annuities (N01700)	returns	observed
pensionDollars	number	Taxable pensions and annuities (A01700)	US dollars	observed
iraReturns	integer	Returns with taxable IRA distributions (N01400)	returns	observed
iraDollars	number	Taxable IRA distributions (A01400)	US dollars	observed
taxableSocialSecurityReturns	integer	Returns with taxable Social Security benefits (N02500)	returns	observed
taxableSocialSecurityDollars	number	Taxable Social Security benefits (A02500)	US dollars	observed
partnershipSCorpReturns	integer	Returns with partnership or S corporation net income or loss (N26270)	returns	observed
partnershipSCorpDollars	number	Partnership and S corporation net income or loss (A26270)	US dollars	observed
charityReturns	integer	Returns itemizing charitable contributions (N19700)	returns	observed
charityDollars	number	Charitable contributions deducted by itemizers (A19700)	US dollars	observed

Floor amendments to ESSB 6346 and their recorded votes

Selected House and Senate floor amendments on the deduction for couples, one-time income, retirement income, farms, pass-through income, charity and a referendum requirement.

Unit of observation: Floor amendment

View this table

amendment_votes.csv text/csv · 3.1 KB (3,155 bytes)

10 field definitions

Field	Type	Meaning	Units	Value type
amendment	string	Amendment document name	—	observed
floorNumber	string	Floor amendment number used in the roll call motion	—	observed
chamber	string	House or Senate	—	observed
sponsor	string	Sponsoring legislator	—	observed
voteDate	date	Date of the roll call	—	observed
rollCallSequence	integer	Roll call sequence number in the Legislature's record	—	observed
yeas	integer	Yea votes	votes	observed
nays	integer	Nay votes	votes	observed
result	string	Adopted or Not adopted	—	observed
officialEffect	string	The amendment's EFFECT statement, verbatim	—	observed

Illustrative households under ESSB 6346 as enacted

Ten households computed from the statute: base = federal AGI less long-term gains, plus Washington capital gains and the capital gains deduction for those owing capital gains tax; tax = 9.9% of base above $1,000,000 less a credit for capital gains tax paid.

Unit of observation: Illustrative household and tax year

View this table

household_examples.csv text/csv · 1.9 KB (1,967 bytes)

14 field definitions

Field	Type	Meaning	Units	Value type
id	string	Example id	—	derived
household	string	Description of the household	—	derived
wages	number	Wages including vested RSUs	US dollars	estimated
retirementIncome	number	Pensions, taxable Social Security and retirement-account distributions	US dollars	estimated
otherOrdinaryIncome	number	Other ordinary income	US dollars	estimated
longTermGainTaxable	number	Long-term capital gain subject to the Washington capital gains tax	US dollars	estimated
exemptGain	number	Gain exempt from the capital gains tax (real estate)	US dollars	estimated
note	string	Rule that drives the result	—	derived
waCapitalGainsTax	number	Washington capital gains tax	US dollars	derived
washingtonBaseIncome	number	Washington base income under Secs. 301-302	US dollars	derived
incomeTaxBeforeCredit	number	9.9% of base income above $1,000,000	US dollars	derived
capitalGainsCredit	number	Nonrefundable credit for capital gains tax (Sec. 205)	US dollars	derived
millionairesTaxOwed	number	ESSB 6346 tax after the credit	US dollars	derived
totalWashingtonTax	number	Capital gains tax plus ESSB 6346 tax	US dollars	derived

Projected paying households under section 316 vs annual indexing

Payers scaled from the Department of Revenue's 25,000 by the threshold's real value relative to 2028, with a Pareto tail parameter of 1.5 or 1.9.

Unit of observation: Tax year

View this table

payer_projection.csv text/csv · 397 bytes

7 field definitions

Field	Type	Meaning	Units	Value type
taxYear	integer	Tax year	—	derived
inflationPct	number	Assumed constant inflation rate	percent per year	estimated
thresholdIn2026DollarsAsWritten	number	Threshold under section 316 in 2026 dollars	2026 US dollars	derived
thresholdIn2026DollarsAnnualIndex	number	Threshold under annual indexing from 2029, in 2026 dollars	2026 US dollars	derived
payersAsWrittenAlpha19	integer	Projected payers under section 316, tail parameter 1.9	households	estimated
payersAsWrittenAlpha15	integer	Projected payers under section 316, tail parameter 1.5	households	estimated
payersAnnualIndex	integer	Projected payers under annual indexing	households	estimated

Supporting files

Source snapshots, manifests, quality reports, documentation, and other materials used to produce or review this release.

• build_reach.js Transformation manifest · text/javascript · 13.7 KB (14,012 bytes)

  Node.js script that builds every table and result from the IRS files, the roll-call XML and the threshold projection.

Saved analyses

Derived from

This dataset uses data from these FactHub dataset versions.

• Washington millionaires tax: who files over $1 million, how the threshold holds up, and how volatile the base is Version 2

Sources

1. Internal Revenue Service, Statistics of Income Primary data: Washington returns by AGI class (files 19in55cmcsv.csv to 22in55cmcsv.csv, e.g. https://www.irs.gov/pub/irs-soi/22in55cmcsv.csv)

   Retrieved October 21, 2026. Public domain (U.S. government work). Unrestricted

   Reliability: Government. Compiled by the IRS from filed individual income tax returns; state tables are published annually with a lag of about three years. Counts are rounded and amounts are in thousands of dollars.

2. Washington State Legislature web services Primary data: recorded floor votes on ESSB 6346 and its amendments

   Retrieved October 21, 2026. Public record of the Washington State Legislature. Public record

   Reliability: Government. The Legislature's official roll-call record, served as XML. Each record gives the motion (floor amendment number and sponsor), date and yea/nay counts.

3. Washington State Legislature Primary record: amendment list, floor numbers, outcomes, and each amendment's official EFFECT statement (texts at lawfilesext.leg.wa.gov/biennium/2025-26/Htm/Amendments/)

   Retrieved October 21, 2026. Public record of the Washington State Legislature. Public record

   Reliability: Government. Official bill page. EFFECT statements are written by nonpartisan legislative staff for each amendment.

4. Washington State Legislature Primary law used for the household calculations (Secs. 201, 205, 301, 302, 314, 316)

   Retrieved October 21, 2026. Public record of the Washington State Legislature. Public record

   Reliability: Government. Enacted session law, chapter 238, Laws of 2026. The Department of Revenue had issued no rules interpreting it as of October 21, 2026.

5. Washington State Legislature Capital gains tax rates, exemptions and deductions used in the household calculations (RCW 82.87.040, .050, .060)

   Retrieved October 21, 2026. Public record of the Washington State Legislature. Public record

   Reliability: Government. Codified statute. RCW 82.87.050 exempts all real estate and retirement-account assets from the capital gains tax.

6. Washington State Standard (via The Inlander) The Department of Revenue's estimate of 25,000 paying households, the starting point of the projection

   Retrieved October 15, 2026. News report; facts only used. Not redistributed; linked

   Reliability: News report. Nonprofit news outlet reporting the Department of Revenue's July 2026 revision of its payer estimate.

Limitations and reproducibility

Reproducible: build_reach.js regenerates every table from the public IRS SOI state files (19-22in55cmcsv.csv), the Washington Legislature's roll-call web service for ESSB 6346, and the threshold projection in FactHub dataset wa-millionaires-tax-reach (versions 1 and 2 hold the same projection). The household examples are deterministic arithmetic from the statute text.

• IRS figures count federal returns, not households, and federal AGI includes long-term capital gains that ESSB 6346 mostly removes from its base, so returns over $1 million of AGI are not the same group as payers of the tax.
• Tax year 2022 is the latest IRS state release used; the tax starts in tax year 2028.
• Return counts for an income type include any return reporting that item, however small; the IRS rounds state counts to the nearest 10.
• The household examples are illustrations of the statute as written, not estimates of how many such households exist. They hold the capital gains standard deduction at its 2025 value of $278,000 and assume no other deductions or credits.
• The payer projection holds real incomes and population constant and uses a Pareto approximation of the income distribution near $1 million, so it isolates the effect of the indexing rule; it is not a forecast. Real income growth would add payers under either indexing rule.
• No public data separates two-earner couples by each spouse's income, so the dataset cannot count couples who pay only because they share one deduction.