Original Medicare (Parts A and B) has no annual cap on what you can spend out of pocket. Unlike most employer or marketplace health plans, there is no maximum dollar amount after which Medicare picks up 100% of your costs for the year. This is one of the biggest gaps in traditional Medicare coverage, and it’s the reason many people buy supplemental insurance. However, other parts of the Medicare system do have caps, and a major new one for prescription drugs took effect in 2025.
Why Original Medicare Has No Spending Cap
Most health insurance plans sold today are required to include an out-of-pocket maximum. Once you hit that number, the plan covers everything else for the rest of the year. Original Medicare does not work this way. As Medicare.gov states directly: “There’s no yearly limit on what you pay out-of-pocket, unless you have supplemental coverage, like a Medicare Supplement Insurance (Medigap) policy, or you join a Medicare Advantage Plan.”
In practice, this means that if you have a serious illness or injury, your 20% coinsurance on Part B services (doctor visits, outpatient procedures, durable medical equipment) keeps accumulating with no ceiling. Someone facing cancer treatment, major surgery, or extended rehabilitation could owe tens of thousands of dollars in a single year, and Original Medicare alone will never stop that meter from running.
Where Medicare Does Have Limits
While there’s no overall annual spending cap, Medicare does place hard limits on certain types of care. These aren’t out-of-pocket maximums in the traditional sense. They’re coverage limits, and once you exceed them, you’re responsible for the full cost.
- Skilled nursing facility care: Part A covers up to 100 days per benefit period. Days 1 through 20 are fully covered after you pay the Part A deductible ($1,736 in 2026). Days 21 through 100 carry a daily coinsurance of $217 in 2026. After day 100, Medicare pays nothing.
- Hospital stays beyond 90 days: Medicare covers 90 days of inpatient hospital care per benefit period. Beyond that, you can draw on 60 lifetime reserve days, each costing $868 per day in 2026. Once those 60 days are used up over the course of your life, they do not renew.
- Home health services: If you qualify, Medicare places no cap on the number of home health visits. However, “part-time or intermittent” care generally means up to 8 hours per day and 28 hours per week of combined skilled nursing and aide services, with the possibility of up to 35 hours per week for short periods if medically necessary.
The New $2,000 Prescription Drug Cap
Starting in 2025, Medicare Part D has a hard annual out-of-pocket cap of $2,000 for prescription drugs. This is the result of the Inflation Reduction Act and represents the first true spending ceiling in the Part D program’s history. Once you’ve paid $2,000 out of pocket for covered prescriptions in a calendar year, your plan covers the rest.
This is a significant change. Before 2025, Part D had a coverage gap (the “donut hole”) and a catastrophic phase where beneficiaries still owed 5% of drug costs indefinitely, meaning people on expensive medications like those for cancer or autoimmune conditions could face bills well above $10,000 a year. That open-ended exposure is now gone for prescription drugs specifically, though it still exists for medical services under Parts A and B.
How Medicare Advantage Adds a Cap
Medicare Advantage plans (Part C) are the main way to get an annual out-of-pocket maximum on medical services. Federal law requires every Medicare Advantage plan to set a yearly cap on what members pay for covered Part A and Part B services. Once you hit that limit, the plan pays 100% for the rest of the year.
These caps vary by plan and can be set for in-network services only or for all services combined. The federal government sets maximum allowable limits each year, and individual plans often choose lower caps to attract enrollees. When shopping for a Medicare Advantage plan, the out-of-pocket maximum is one of the most important numbers to compare, because it determines your worst-case financial exposure for the year.
How Medigap Policies Handle the Gap
If you prefer to stay on Original Medicare rather than switching to Medicare Advantage, Medigap (Medicare Supplement Insurance) policies are the other route to limiting your costs. Most Medigap plans work by covering your coinsurance and copayments so that your actual spending stays low, but two specific plans include a defined out-of-pocket maximum.
Medigap Plan K has an annual out-of-pocket limit of $8,000 in 2026. Plan L has a limit of $4,000. Both plans cover a smaller share of your coinsurance costs than more comprehensive Medigap options, but once you reach the limit, they cover 100% of Medicare-approved costs for the rest of the year. Other Medigap plans (like Plan F or Plan G) don’t technically have a cap because they cover so much of your cost-sharing that your exposure is already minimal.
The tradeoff is straightforward: Medigap premiums are an additional monthly cost on top of your Part B premium, and they can be substantial depending on your age, location, and the plan you choose. But for people who want the freedom to see any provider that accepts Medicare while still having financial protection, Medigap fills the gap that Original Medicare leaves wide open.
What This Means in Practice
If you’re on Original Medicare with no supplemental coverage, you have no annual spending cap on medical services. Your financial risk in a bad health year is essentially unlimited. You do now have a $2,000 cap on prescription drug costs thanks to Part D changes, but that applies only to medications, not to hospital stays, surgeries, or outpatient care.
To get a true out-of-pocket maximum on medical services, you need either a Medicare Advantage plan or a Medigap policy. Each approach has different tradeoffs in terms of provider networks, monthly premiums, and plan flexibility, but both accomplish the same core goal: putting a ceiling on what a single year of health care can cost you.