Editorial Policy

CostByState covers money — a topic where a wrong number can cost someone real money. This policy describes how we produce content and keep it accurate.

Sourcing and citation

Every number on the Site traces to a named source, shown with the date the source data describes. We prioritize official primary sources (IRS, Census, BEA, BLS, EIA, Freddie Mac, and state revenue departments) and never present a figure in prose that isn't backed by our underlying data. See our methodology for the full source list and formulas.

How content is produced

Data is gathered by an automated pipeline and reviewed by a person before publishing. Written explanations may be drafted with AI assistance, but every draft is fact-checked by a human against the underlying data, and any figure quoted in text is rendered from the same data that powers the calculators — so prose and tools can never disagree.

Fact-checking and review

• Tax logic is unit-tested against published federal and state schedules.
• Monthly data changes are reviewed and approved through a pull request before going live.
• Values that move sharply month-over-month are flagged for a closer look.

Corrections

If we get something wrong, we fix it promptly and, for material errors, note what changed. If you spot an error, please contact us — reader corrections are one of our most valuable quality checks.

Independence and advertising

We display advertising to fund the Site, and advertising never influences our data or explanations. Our figures are derived from public sources, not from advertisers.

Authorship

Editorial responsibility rests with Michael Dang, Founder. Data studies are published under the CostByState Research Team byline.