Federal income tax is the tax paid to the U.S. federal government based on your taxable income each year. It is separate from other taxes withheld from your paycheck, such as Social Security, Medicare (payroll taxes), state income taxes, and local taxes. Your federal income tax liability is determined by your taxable income and filing status, which together place you within the progressive tax bracket system. Understanding how federal income taxes work is foundational to budgeting, tax planning, and maximizing your take-home pay.