Where your tax dollars go, in rough order of size: Social Security, health programs like Medicare and Medicaid, national defense, and interest on the national debt swallow most of the federal budget, while state and local taxes fund a separate layer covering public schools, police, roads, and water. The federal government spent about $7 trillion in fiscal year 2025, funded mostly by the income and payroll taxes withheld from paychecks.1U.S. Treasury Fiscal Data. Federal Spending Here is what each of the big pieces actually pays for.
Social Security Is the Single Biggest Line Item
Social Security consumes about 21 percent of all federal spending. In fiscal year 2024 that came to roughly $1.5 trillion in retirement, survivor, and disability payments. It runs on what budget analysts call mandatory spending: permanent law sets the eligibility rules, and anyone who meets them gets paid regardless of what Congress does in a given year.2Office of the Law Revision Counsel. 42 U.S.C. Chapter 7 – Social Security
The program is funded by the 6.2 percent Social Security tax taken out of your wages, matched by another 6.2 percent from your employer, and applied only to the first $184,500 you earn in 2026. Self-employed workers pay both halves, so 12.4 percent.3Social Security Administration. Contribution and Benefit Base Benefits rise automatically with inflation each year. The 2026 cost-of-living adjustment came in at 2.8 percent.4Social Security Administration. 2026 Cost-of-Living Adjustment (COLA) Fact Sheet That built-in growth, combined with more baby boomers retiring, has been pushing Social Security’s share of the budget steadily upward for decades.
Health Programs Take the Largest Combined Share
Grouped together, federal health insurance programs consume roughly a quarter of all federal dollars, more than any other category. Medicare alone accounted for about 13 percent of federal outlays in recent years, covering people 65 and older along with certain younger people who are blind or disabled.5USAFacts. How Much Does Medicare Cost the Federal Government Like Social Security, it is mandatory spending driven by the number of eligible beneficiaries. It is funded by the 1.45 percent Medicare tax on all wages (matched by your employer, with no income cap), plus a 0.9 percent surtax on wages above $200,000 for single filers or $250,000 for joint filers.
Medicaid is structured differently. The federal government and the states split the cost of covering low-income residents, with the federal share varying by state. Combined federal spending on Medicaid and the Children’s Health Insurance Program runs into the hundreds of billions annually, and Affordable Care Act marketplace subsidies add another layer. Health programs are growing faster than nearly any other part of the budget, which is why they anchor almost every serious spending debate.
Defense and the Rest of What Congress Chooses Each Year
Defense is the largest piece of the budget that Congress actively decides on every year through appropriations bills. The Department of Defense budget request for fiscal year 2025 was $849.8 billion, and the fiscal year 2026 request stayed at a similar scale.6U.S. Department of War. Department of Defense Releases the Presidents Fiscal Year 2025 Defense Budget Those dollars pay for service member salaries, equipment, weapons, and operations around the world. Defense has run roughly 13 to 15 percent of total federal spending in recent years, though it eats up more than half of the discretionary portion Congress votes on.
Twelve annual appropriations bills fund everything else in the discretionary category.7House Committee on Appropriations. The Appropriations Committee: Authority, Process, and Impact That includes veterans’ healthcare, federal education grants for low-income schools and special education, transportation infrastructure like interstate highways and air traffic control, scientific research, foreign aid, the federal court system, the FBI, the National Park Service, and every other federal agency. This is the part of the budget where political priorities show up most plainly, because lawmakers can raise, cut, or redirect the funding each cycle. It has also been shrinking as a share of the total for decades, squeezed by mandatory programs and interest costs.
Interest on the National Debt
When the government spends more than it collects, it borrows the difference by selling Treasury bills, notes, and bonds.8TreasuryDirect. FAQs About the Public Debt The interest on that accumulated borrowing has quietly become one of the biggest items in the budget. In fiscal year 2025, interest consumed roughly 14 percent of all federal spending, close to $1 trillion for the year. That is more than the government spent on defense.
Gross national debt stood at $38.40 trillion as of December 2025, having grown by more than $2 trillion in a single year.9Joint Economic Committee. National Debt Hits 38.40 Trillion The projected federal deficit for fiscal year 2025 was $1.8 trillion, meaning the government borrowed roughly a quarter of what it spent. Interest costs are locked in by the terms of previously issued bonds and current market rates, so Congress cannot negotiate them down. If rates stay high, this line item will keep crowding out room for everything else.
Where State and Local Taxes Go
Federal taxes are only part of what comes out of your pocket. State and local governments collect their own revenue through income taxes, sales taxes, and property taxes, and they spend it on the services you actually see day to day. The mix varies sharply by where you live. Eight states impose no individual income tax and make up the difference through higher property taxes, broader sales taxes, or natural resource revenues. Texas leans heavily on local property taxes; Washington State runs one of the highest combined sales tax rates in the country.
Education is the single largest expense at the state and local level, about 21 percent of their direct spending. Property taxes and state income taxes pay for teacher salaries, school buildings, and classroom materials, with local school boards making most of the decisions. The federal government adds supplemental funding for narrow purposes like special education and low-income student support, but the bulk of K-12 money is raised locally.
After education come public welfare programs (including each state’s share of Medicaid), public safety, and infrastructure. Police, fire departments, road paving, bridge maintenance, water systems, and trash collection all run on local tax revenue. Because elected local officials manage these services, the link between the tax and the service is usually easier to see than at the federal level. Combined state and local sales tax rates run from zero in a handful of states to over 10 percent in others, and effective property tax rates span from under 0.3 percent to above 2 percent of a home’s value, so the total burden depends heavily on your zip code.
Which Taxes Pay for Which Programs
Federal revenue topped $5.2 trillion in fiscal year 2025, with individual income taxes providing more than half of that total.10Congressional Budget Office. Revenues in Fiscal Year 2025: An Infographic Income taxes flow into the general fund, which pays for defense, discretionary programs, most of Medicaid, and interest on the debt. Payroll taxes are dedicated: the Social Security portion funds Social Security, and the Medicare portion funds Medicare’s hospital insurance. Corporate income taxes and excise taxes on goods like fuel and tobacco make up most of what remains.
That split matters when you hear debates about the trust funds running short. Social Security and Medicare hospital insurance are legally tied to the payroll taxes that fund them, so their long-term math depends on how many workers are paying in versus how many beneficiaries are drawing out. Everything else competes for the general fund, and that pool is what shrinks as interest payments climb.