Your Medicare premium depends on several factors: which parts of Medicare you have, how long you or your spouse worked, your income from two years ago, and whether you signed up on time. Most people pay $185 per month for Part B in 2025 and nothing for Part A, but higher earners, late enrollees, and those with shorter work histories pay significantly more.
Part A: Work History Sets Your Premium
Part A covers hospital stays, skilled nursing, and hospice care. Most people pay $0 because they or a spouse paid Medicare taxes for at least 10 years (40 quarters). If you don’t meet that threshold, you’ll buy into Part A at one of two price points: $311 per month if you have 30 to 39 quarters of work history, or $565 per month if you have fewer than 30 quarters. There’s no income adjustment for Part A, so these amounts apply regardless of how much you earn.
Part B: The Standard Premium and How Income Changes It
Part B covers doctor visits, outpatient care, and preventive services. The standard monthly premium for 2025 is $185.00, with an annual deductible of $257. The federal government sets this amount each year based on projected program costs, and it applies to the vast majority of enrollees.
If your income is above a certain level, you’ll pay more through what’s called an income-related monthly adjustment amount, or IRMAA. Social Security uses your modified adjusted gross income (MAGI) from your tax return two years prior. So for 2026 premiums, the agency looks at your 2024 tax return (or 2023 if 2024 isn’t available yet).
For single filers, the surcharges for 2026 kick in above $109,000 in income. For married couples filing jointly, the threshold is $218,000. Above those levels, your Part B premium rises in steps:
- Single $109,001 to $137,000 (joint $218,001 to $274,000): $284.10 per month
- Single $137,001 to $171,000 (joint $274,001 to $342,000): $405.80 per month
- Single $171,001 to $205,000 (joint $342,001 to $410,000): $527.50 per month
- Single $205,001 to $499,999 (joint $410,001 to $749,999): $649.20 per month
- Single $500,000 or more (joint $750,000 or more): $689.90 per month
If you’re married but file separately, the brackets are compressed. Income above $109,000 jumps you to $649.20 per month, and $391,000 or more triggers the top tier of $689.90. This filing status is the most penalized under IRMAA, which catches some couples off guard.
If your income has dropped significantly since the tax year Social Security is using (because of retirement, divorce, death of a spouse, or a work reduction), you can request a reconsideration. You’ll need to contact Social Security and provide documentation of the life-changing event.
Part D: Plan Choice Plus Income Adjustments
Part D covers prescription drugs, and the premium varies by which plan you choose. Plans set their own monthly rates based on the drugs they cover, pharmacy networks, and cost-sharing structures. You’ll compare options during open enrollment each fall.
On top of your plan’s premium, higher-income enrollees pay an IRMAA surcharge for Part D as well. The income thresholds mirror Part B exactly. For 2026, single filers above $109,000 (or joint filers above $218,000) pay an extra $14.50 to $91.00 per month depending on income tier, added directly to their plan premium.
Medicare Advantage: How Private Plans Set Prices
Medicare Advantage (Part C) plans are offered by private insurers as an alternative to original Medicare. Each year, these companies submit bids to the federal government estimating how much it will cost them to cover a standard Medicare beneficiary. A qualified actuary must certify each bid. The bid breaks down costs for basic medical benefits, prescription drug coverage, and any supplemental benefits like dental or vision.
The government compares each plan’s bid against a benchmark amount calculated at the county level. If the bid comes in below the benchmark, the insurer gets to keep a portion of the savings, which it must return to enrollees as extra benefits or lower premiums. If the bid exceeds the benchmark, enrollees pay the difference as an additional monthly premium on top of their Part B premium. This is why some Medicare Advantage plans charge $0 extra while others cost $50 or more per month, and why premiums for the same plan can differ by county.
Late Enrollment Penalties
Signing up late for Part B or Part D permanently increases your premium. These aren’t one-time fees. They’re added to your monthly bill for as long as you have Medicare.
For Part B, the penalty is 10% for every full 12-month period you were eligible but didn’t enroll. If you delayed two years past your initial enrollment window without qualifying for a special enrollment period (such as through an employer plan), your premium goes up 20% for life. On a $185 base premium, that’s an extra $37 every month, indefinitely.
For Part D, the penalty is 1% of the national base beneficiary premium for each full month you went without creditable drug coverage. That base premium is $38.99 in 2026. So if you went 18 months without coverage, you’d owe an extra 18% of $38.99, or roughly $7 per month, added permanently. The penalty recalculates each year as the base premium changes.
The Hold Harmless Rule
Most people have their Part B premium deducted directly from their Social Security check. A federal rule called the “hold harmless provision” prevents your Social Security payment from shrinking because of a Part B premium increase. If the annual cost-of-living adjustment to your Social Security benefit isn’t large enough to cover the Part B premium increase, your premium stays the same and your check doesn’t drop.
This protection has limits. It doesn’t apply if you’re enrolling in Part B for the first time, if you pay an IRMAA surcharge, or if Medicaid pays your premium. In years with a large Social Security cost-of-living adjustment, nearly everyone’s benefit increase is big enough to absorb the premium hike, so the provision doesn’t come into play for most people. But in years with a small or zero adjustment, it can keep premiums frozen for millions of enrollees while first-time enrollees and higher earners absorb a larger share of program costs.
What Actually Drives Year-to-Year Changes
CMS recalculates the Part B premium annually based on projected spending for doctor visits, outpatient services, and other Part B benefits. When health care costs rise faster than expected, or when the Medicare trust fund needs shoring up, premiums climb. The Part B premium has roughly tripled over the past 20 years, though year-to-year jumps are usually modest, in the range of $5 to $15 for most enrollees.
Your personal premium in any given year is ultimately a combination of the standard base rate, any IRMAA surcharge based on your income two years prior, any late enrollment penalty you’ve accumulated, and the hold harmless protection if it applies. Reviewing your Social Security IRMAA notice each fall, when the new year’s rates are announced, is the simplest way to confirm what you’ll owe.