Medicare is paid for through a combination of payroll taxes, general federal revenue, and premiums paid by beneficiaries. The mix varies depending on which part of Medicare you’re looking at, but if you’re a working American, you’re already contributing through every paycheck. Here’s how each funding stream works and what it means for you.
Payroll Taxes Fund Hospital Coverage (Part A)
The most visible way Medicare is funded is through the payroll tax you see on every pay stub. Employees pay 1.45% of their wages, and employers match that with another 1.45%, for a combined rate of 2.9%. If you’re self-employed, you pay the full 2.9% yourself. Unlike Social Security, there’s no cap on earnings subject to the Medicare tax. Every dollar you earn is taxed.
This payroll tax flows into the Hospital Insurance Trust Fund, which finances Part A (hospital stays, skilled nursing care, and hospice). About three-quarters of Part A’s annual income comes from payroll taxes, according to the Congressional Budget Office. Roughly one-eighth comes from income taxes that higher-earning retirees pay on their Social Security benefits. The remainder comes from interest on the trust fund’s reserves and smaller sources.
If you earn above $200,000 as an individual (or $250,000 filing jointly), you pay an additional 0.9% Medicare tax on wages above that threshold. Your employer does not match this extra amount. It was added in 2013 specifically to strengthen Medicare’s finances.
General Tax Revenue Covers Most of Parts B and D
Parts B and D are funded very differently from Part A. Rather than relying on a dedicated payroll tax, they draw most of their money from the federal government’s general revenue, which means income taxes and other broad tax collections.
For Part B, which covers doctor visits, outpatient services, and preventive care, general revenue provides about 71% of the funding. Beneficiary premiums account for 27%, with interest and other sources covering the remaining sliver. For Part D, the prescription drug benefit, general revenue covers about 73%. Beneficiary premiums contribute 14%, and states kick in roughly 12% through payments for people who are enrolled in both Medicare and Medicaid.
This means the majority of Part B and D spending is ultimately funded by all federal taxpayers, not just Medicare beneficiaries or workers paying the Medicare payroll tax. It also means these programs can’t technically “go broke” the way Part A can, because Congress authorizes general revenue transfers to cover whatever premiums don’t.
What Beneficiaries Pay in Premiums
Most people don’t pay a premium for Part A. If you or your spouse paid Medicare taxes for at least 10 years (40 quarters), Part A is premium-free. The standard monthly premium for Part B in 2025 is $185.00. Part D premiums vary by plan but are generally modest, since federal subsidies cover the bulk of the program’s costs.
Beyond premiums, beneficiaries share costs through deductibles and coinsurance when they actually use services. These out-of-pocket costs are a meaningful part of Medicare’s overall financing picture, though they represent a smaller slice than payroll taxes or general revenue.
Higher Earners Pay More
Medicare uses an income-based surcharge called IRMAA (Income-Related Monthly Adjustment Amount) to charge higher premiums to wealthier beneficiaries. The adjustment is based on your tax return from two years prior.
For 2025, here’s how Part B premiums scale with income for individual filers:
- $106,000 or less: $185.00 per month (standard premium, no surcharge)
- $106,001 to $133,000: $259.00 per month
- $133,001 to $167,000: $370.00 per month
- $167,001 to $200,000: $480.90 per month
- $200,001 to $499,999: $591.90 per month
- $500,000 or more: $628.90 per month
For married couples filing jointly, the thresholds are roughly double. At the highest tier, you’d pay more than three times the standard premium. Part D has a similar income-based surcharge structure. These higher premiums affect only about 7% of Medicare beneficiaries, but they do bring in additional revenue.
State Contributions for Dual-Eligible Beneficiaries
States also contribute to Medicare’s funding in one specific way. When Medicare Part D took over prescription drug coverage for people who had previously been covered by Medicaid, states were required to make monthly “clawback” payments to the federal government. These payments represent a portion of what states would have spent on drug coverage for those dual-eligible beneficiaries. In 2023, state payments accounted for about 12% of Part D revenue.
Where the Money Actually Goes
Medicare spends very little on overhead compared to private insurance. Traditional Medicare (Parts A, B, and D) spent just 1.35% of benefit payments on administration in 2018. Medicare Advantage plans (Part C), which are run by private insurers, had administrative costs closer to 11-15% of benefits. The vast majority of Medicare dollars go directly to hospitals, doctors, drug manufacturers, and other providers.
The Trust Fund Solvency Question
Because Part A relies on a dedicated revenue stream, it faces a real solvency timeline. The Hospital Insurance Trust Fund is projected to be able to pay 100% of scheduled benefits until 2033, according to the 2025 Medicare Trustees Report. After that, incoming payroll taxes would still cover about 89% of costs, but Congress would need to act to fill the gap, whether through higher taxes, reduced spending, or some combination.
Parts B and D don’t face this same cliff because they’re automatically topped up by general revenue each year. Their financial pressure shows up differently: as a growing share of the overall federal budget rather than a specific trust fund running dry.
In practical terms, Medicare is funded by nearly every American. Workers pay through payroll taxes. All taxpayers contribute through general revenue. Beneficiaries pay through premiums and cost-sharing. And higher earners pay at both ends, through the additional Medicare tax on wages and through income-adjusted premiums in retirement.