Official Tax Data References

Every tax figure on GetTaxCalculator is sourced from an official government publication. This page lists all primary sources used across the site. If you find a discrepancy between our data and any of these sources, please report it to [email protected].

Federal |IRS

• IRS Revenue Procedure 2025-32 |2026 inflation adjustments for tax brackets, standard deductions, and other provisions
• IRS 2026 Tax Brackets Newsroom |Summary of tax year 2026 inflation adjustments
• IRS Child Tax Credit |Current Child Tax Credit rules, amounts, and phase-outs
• IRS Self-Employment Tax |SE tax rates, calculation methodology, and deductible portion
• IRS Estimated Taxes |Quarterly estimated tax payment rules and safe harbor thresholds
• IRS Form 2210 |Underpayment of Estimated Tax penalty calculation
• IRS Publication 590-B |Required Minimum Distribution (RMD) tables and rules
• IRS W-2/W-3 Instructions (2026) |Wage reporting, withholding, and employer tax obligations
• IRS Additional Medicare Tax |0.9% Additional Medicare Tax thresholds and calculation

Federal |OBBBA / Statute

• OBBBA (Public Law 119-1) |One Big Beautiful Bill Act full text
• IRC §224 (Tips Deduction) |Above-the-line deduction for tip income
• IRC §225 (Overtime Deduction) |Above-the-line deduction for overtime pay

Federal |SSA

• SSA Contribution and Benefit Base |Social Security wage base and FICA rate history

Federal |ACA

• HHS Federal Poverty Level Guidelines |Poverty thresholds used for ACA subsidy eligibility
• Healthcare.gov |Official ACA marketplace and subsidy information
• IRS Premium Tax Credit |IRC §36B applicable percentage tables and Premium Tax Credit rules

State Revenue Departments

Each state's tax data is sourced from the official revenue department or equivalent agency. All 50 states and the District of Columbia are listed alphabetically below.

• Alabama |Department of Revenue
• Alaska |Department of Revenue, Tax Division
• Arizona |Department of Revenue
• Arkansas |Department of Finance and Administration
• California |Franchise Tax Board
• Colorado |Department of Revenue
• Connecticut |Department of Revenue Services
• Delaware |Division of Revenue
• District of Columbia |Office of Tax and Revenue
• Florida |Department of Revenue
• Georgia |Department of Revenue
• Hawaii |Department of Taxation
• Idaho |State Tax Commission
• Illinois |Department of Revenue
• Indiana |Department of Revenue
• Iowa |Department of Revenue
• Kansas |Department of Revenue
• Kentucky |Department of Revenue
• Louisiana |Department of Revenue
• Maine |Revenue Services
• Maryland |Comptroller of Maryland
• Massachusetts |Department of Revenue
• Michigan |Department of Treasury
• Minnesota |Department of Revenue
• Mississippi |Department of Revenue
• Missouri |Department of Revenue
• Montana |Department of Revenue
• Nebraska |Department of Revenue
• Nevada |Department of Taxation
• New Hampshire |Department of Revenue Administration
• New Jersey |Division of Taxation
• New Mexico |Taxation and Revenue Department
• New York |Department of Taxation and Finance
• North Carolina |Department of Revenue
• North Dakota |Office of State Tax Commissioner
• Ohio |Department of Taxation
• Oklahoma |Tax Commission
• Oregon |Department of Revenue
• Pennsylvania |Department of Revenue
• Rhode Island |Division of Taxation
• South Carolina |Department of Revenue
• South Dakota |Department of Revenue
• Tennessee |Department of Revenue
• Texas |Comptroller of Public Accounts
• Utah |State Tax Commission
• Vermont |Department of Taxes
• Virginia |Department of Taxation
• Washington |Department of Revenue
• West Virginia |State Tax Department
• Wisconsin |Department of Revenue
• Wyoming |Department of Revenue