Top 10 US States by Individual Income Tax Top Rate

PlainTaxCalc ranks US states by individual income tax top marginal rate, updated automatically as state revenue departments publish new schedules.

Research period: 2026-05-16

Research question

Across US states and the District of Columbia, which carry the highest individual income tax top marginal rates, and how does the top of the distribution compare to states with no broad-based income tax?

Methodology

This ranking reflects the current dataset, sourced from the agency referenced in the citation below and updated automatically as new filings are processed.

Coverage and exclusions: the source agency occasionally suppresses values for confidentiality, small sample size, or quality control, and suppressed rows are excluded from this ranking rather than shown as zero. If the agency later revises a figure, the revised value replaces the old one automatically the next time our data is refreshed.

Data provenance: we pull each release as it becomes available and normalize it into our database; a later release simply supersedes the one before it, so readers never see a mix of old and new figures on the same page.

Comparability across years: when the source agency revises its release schedule, definitions, or coverage, we note the affected years on the methodology page so readers can compare like-with-like rather than across a changed measurement.

Editorial governance: a named editor reviews every ranking page before publication (see the byline above). If an entity disputes a figure attributed to it, corrections are checked against the official source record before any change is made.

Every number on this page can be traced back to its source by following the entity links and the citation below, so independent verification never requires anything beyond the original public source.

See the methodology page for the complete data-update process, source vintage, and field definitions.

The ranked top 10

Every row below reflects the current 10-record dataset. Reload the page after new data is processed to see the latest values.

#	State	Top marginal rate	Code	Notes
1	Idaho	0.053	ID	Flat 5.3% rate (retroactively reduced from 5.695% via H.B. 40, March 2025).
2	Georgia	0.052	GA	Flat 5.19% rate for 2025-2026 (phasing down from 5.39%; further cuts if revenue triggers are met).
3	Illinois	0.05	IL	Flat 4.95% rate. Constitutional uniformity clause requires flat tax.
4	Utah	0.045	UT	Flat 4.5% rate (reduced from 4.55% via H.B. 106, retroactive to Jan 1 2025).
5	Colorado	0.044	CO	Flat 4.40% rate (TABOR refund mechanism).
6	Michigan	0.043	MI	Flat 4.25% rate.
7	Mississippi	0.04	MS	Flat 4.0% rate effective 2026 (final step of the phasedown from 4.4% in 2025).
8	North Carolina	0.04	NC	Flat 3.99% rate effective Jan 1 2026 (reduced from 4.25%; further trigger-based cuts through 2028).
9	Iowa	0.038	IA	Flat 3.8% rate effective 2025 (reduced from 3.9%).
10	Kentucky	0.035	KY	Flat 3.5% rate effective Jan 1 2026 (reduced from 4.0% via H.B. 1, Feb 2025).

Source: U.S. State Revenue Departments, State individual income tax schedules curated from state revenue-department filings. Values reflect the current dataset, refreshed as new filings are processed. U.S. State Revenue Departments, State individual income tax schedules curated from state revenue-department filings. Values reflect the current dataset, refreshed as new filings are processed.

Findings

Top entity in the ranking

The top-ranked record in this dataset is Idaho, with a value of 0.053 on the Top marginal rate column. The full top-10 set is rendered in the table above. Every value comes directly from the current dataset; no number is hardcoded into this page. When the source agency publishes a revision, the ranking and the prose around it update automatically.

Distribution shape

The gap between the top-ranked record (0.053) and the 10th-ranked record (0.035) characterizes how concentrated the top of the distribution is. Where the top value is many multiples of the median value of the visible set, the population is highly concentrated, a small number of entities accumulate the bulk of the measured quantity. Where the top and bottom of the visible set are close together, the distribution is relatively flat across the top end. The full distribution beyond this top-10 cut is summarized in the aggregate context section below and explored in the linked entity profiles.

Aggregate context

Across the full population behind this ranking, here are the summary statistics: how many records exist in total, the sum of the ranking metric across all qualifying records, and the mean per-record value. The methodology page documents the exact filter applied (records with null or zero values on the ranking metric are excluded). This aggregate row is computed from the same dataset that powers the ranking above.

Source provenance

The records in this ranking originate from U.S. State Revenue Departments, specifically the State individual income tax schedules curated from state revenue-department filings. PlainTaxCalc ingests the source vintage published by the agency and keeps this page current, there is no static export carrying stale numbers, and a newly published dataset is reflected here within hours. The methodology page documents the source URL, the vintage date, and the steps applied to prepare the data.

Why this ranking matters

Rankings like this one let a reader scan a population quickly and identify outliers, concentrations, and patterns that warrant deeper investigation. The detail pages linked from each entity in the table above give the full per-entity context: time-series history where available, related metrics from adjacent tables, and links onward to the underlying source records. The methodology page explains how an entity earns inclusion in the dataset and how the ranking column is computed at the source.

What this analysis cannot tell us

State top marginal rate is the headline number, not the effective tax rate. Households pay the top rate only on income above the top bracket threshold; effective rates are materially lower for most filers. State brackets also vary widely in their threshold structures, California's top rate applies above a high threshold while some states reach their top rate at much lower income levels, producing larger effective burdens at middle incomes. Some states with no broad-based income tax (FL, TX, WA, NV, SD, WY, AK) still levy state-level taxes on specific income categories or impose comparatively higher sales or property taxes. New Hampshire historically taxed only interest and dividends and is phasing that tax out; Tennessee fully phased out its Hall income tax. The has_income_tax flag may not capture nuances like local-level taxes (e.g. NYC supplemental rate on top of NY state, KY county-level occupational taxes). Tax rates and brackets change via state legislation; this dataset reflects the most recent published vintage. Filing-status-specific brackets (single, MFJ, HoH) are tracked separately but not always reflected in the headline top-rate figure.

Sources

Tax Foundation, State Individual Income Tax Rates and Brackets - https://taxfoundation.org/data/all/state/state-income-tax-rates/
Federation of Tax Administrators, State Tax Rates - https://www.taxadmin.org/
State Revenue Department Filings, Individual Income Tax Schedules - https://www.taxadmin.org/state-tax-agencies