Data Sources & Regulatory Citations

Internal Revenue Service (IRS)

Defines official inflation-adjusted statutory brackets for Single, MFJ, MFS, and HOH filers, and standard deductions ($16,100 Single/MFS, $32,200 MFJ, $24,150 HOH).

Internal Revenue Service (IRS)

Standard deductions ($15,750 Single/MFS, $31,500 MFJ, $23,625 HOH) and statutory income brackets for tax year 2025.

Social Security Administration (SSA)

Statutory maximum taxable earnings limit for Social Security (OASDI) is $184,500. Employee rate is 6.2% ($11,439.00 max employee tax).

United States Congress / Internal Revenue Code

Defines employee tax rates: 6.2% Old-Age, Survivors, and Disability Insurance (§ 3101(a)); 1.45% Hospital Insurance Medicare (§ 3101(b)(1)); 0.9% Additional Medicare Tax on wages exceeding statutory thresholds (§ 3101(b)(2)).

United States Congress / Internal Revenue Code

Mandates that employers withhold the 0.9% Additional Medicare Tax once an employee's wages exceed $200,000 in a calendar year, regardless of filing status.

State Departments of Revenue & Taxation

Verifies the 9 US states without broad-based earned wage income tax. New Hampshire Interest & Dividends tax full repeal took effect Jan 1, 2025; Washington earned wage tax is $0 (capital gains tax applies only to high-net-worth gains).

Consumer Financial Protection Bureau (CFPB)

Sets federal rules for APR definitions, finance charge disclosures, loan amortization, and monthly payment schedules.

Federal Reserve Board / CFPB

Specifies the mathematical relationship between nominal annual interest rates, compounding frequency, and Annual Percentage Yield (APY): APY = 100 * [(1 + Interest/Principal)^(365/Days) - 1].

United States Congress / CFPB

Mandates minimum payment warning disclosures on billing statements and sets standards for minimum repayment calculations.