Tax Data Sources

Primary government publications and agency pages used by the calculation engine. A source link does not mean the agency endorses this calculator.

Source inventory last reviewed October 4, 2026

Federal Sources

2025 federal brackets and standard deductions

Internal Revenue Service

Open official source

2026 federal brackets and standard deductions

Internal Revenue Service

Open official source

Social Security wage base

Social Security Administration

Open official source

Social Security and Medicare tax rates

Internal Revenue Service

Open official source

Additional Medicare Tax

Internal Revenue Service

Open official source

401(k) contribution limits

Internal Revenue Service

Open official source

State & District Sources

These links are collected from every state-tax and employee payroll-program line returned by the live 2026 calculation path.

JurisdictionCodeOfficial source
AlabamaAL
AlaskaAK
ArizonaAZ
ArkansasAR
CaliforniaCA
ColoradoCO
ConnecticutCT
DelawareDE
District of ColumbiaDC
FloridaFL
GeorgiaGA
HawaiiHI
IdahoID
IllinoisIL
IndianaIN
IowaIA
KansasKS
KentuckyKY
LouisianaLA
MaineME
MarylandMD
MassachusettsMA
MichiganMI
MinnesotaMN
MississippiMS
MissouriMO
MontanaMT
NebraskaNE
NevadaNV
New HampshireNH
New JerseyNJ
New MexicoNM
New YorkNY
North CarolinaNC
North DakotaND
OhioOH
OklahomaOK
OregonOR
PennsylvaniaPA
Rhode IslandRI
South CarolinaSC
South DakotaSD
TennesseeTN
TexasTX
UtahUT
VermontVT
VirginiaVA
WashingtonWA
West VirginiaWV
WisconsinWI
WyomingWY

Local Sources

New York City resident income tax

New York Department of Taxation and Finance

Philadelphia, PA

Official local source

Pittsburgh, PA, Scranton, PA, Allentown, PA, Reading, PA, Erie, PA, Lancaster, PA, Harrisburg, PA, State College, PA

Official local source

Cincinnati, OH

Official local source

Grand Rapids, MI

Official local source

Marion County (Indianapolis), IN, Lake County, IN, Allen County (Fort Wayne), IN, Hamilton County (Carmel/Fishers), IN, Monroe County (Bloomington), IN

Official local source

Louisville / Jefferson County, KY

Official local source

Lexington / Fayette County, KY

Official local source

Kansas City, MO

Official local source

Found a Discrepancy?

Government pages may change after a tax update. Include the jurisdiction, tax year, expected rate, and official source when reporting an issue.

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