Why Your Hospital Bill Keeps Climbing: What Medicare Must Know

If you've opened a hospital bill in the last decade and felt your stomach drop, you're not imagining things. Hospital prices in the United States have risen far faster than general inflation, and the reasons why are tangled up in decades of federal policy decisions that most Medicare beneficiaries never hear about. Understanding what's driving those costs — and how they flow through to your Medicare premiums, deductibles, and out-of-pocket bills — is one of the most practical things you can do to protect your health care budget in retirement.

The core problem is consolidation. Over the past 30 years, thousands of independent hospitals, physician practices, and outpatient clinics have been absorbed into large hospital systems. In 1990, most communities had several competing hospitals and hundreds of independent doctors. Today, research from the American Hospital Association and independent health policy analysts consistently shows that the majority of U.S. hospital markets are now considered 'highly concentrated,' meaning one or two large systems dominate. When hospitals don't have to compete for patients, they have far less pressure to keep prices reasonable. Studies published in health economics journals have found that hospital mergers in already-concentrated markets can raise prices by 20% to 40% or more — costs that ultimately get passed along to Medicare, Medicaid, private insurers, and patients.

What many people don't realize is that federal Medicare payment policy has actively encouraged this consolidation, often unintentionally. One of the clearest examples is what policy analysts call the 'site-of-service' payment differential. Under traditional Medicare rules, if you go to an independent cardiologist's office for an echocardiogram, Medicare pays one rate. But if that same cardiologist's office gets purchased by a hospital system and rebranded as a 'hospital outpatient department,' Medicare suddenly pays a dramatically higher rate for the exact same test performed by the exact same doctor in the exact same building. The difference can be substantial — in 2024, Medicare paid roughly $180 for an echocardiogram at an independent physician office but over $450 at a hospital outpatient department, according to CMS payment data. That gap gives hospital systems a powerful financial incentive to acquire physician practices, and it gives physicians a financial incentive to sell. The patient gets no additional benefit. The taxpayer and the Medicare trust fund pay more.

This dynamic has a direct impact on what you pay as a Medicare beneficiary. Under Original Medicare in 2025, the Part A hospital deductible is $1,676 per benefit period — and there is no cap on how many benefit periods you can have in a year. The Part B deductible is $257, and you're responsible for 20% of most outpatient costs with no out-of-pocket maximum. When hospital systems charge more — and Medicare's own payment formulas reward them for doing so — your 20% coinsurance grows right along with it. A procedure that costs $5,000 at an independent facility might cost $8,000 at a hospital outpatient department, and your share jumps from $1,000 to $1,600 for the exact same care. Multiply that across several procedures in a year and the difference becomes significant on a fixed income.

Reform advocates, including the Paragon Health Institute and the Medicare Payment Advisory Commission (MedPAC), have long pushed for 'site-neutral payments' — a policy that would pay the same rate for the same service regardless of whether it's delivered in a hospital-owned facility or an independent one. MedPAC estimated in its 2023 report to Congress that site-neutral payment reform could save Medicare tens of billions of dollars annually. Congress has taken partial steps in this direction, but full implementation has faced fierce lobbying resistance from hospital industry groups. In the meantime, beneficiaries continue to absorb the cost differential.

Consolidation also affects your access to care in ways that aren't immediately obvious. When a large hospital system acquires the only orthopedic group or the only gastroenterology practice in a region, it can effectively force Medicare Advantage plans to include that system in their network — or leave beneficiaries with no in-network specialists at all. This gives dominant hospital systems enormous leverage in contract negotiations with insurers, which is one reason Medicare Advantage premiums and out-of-pocket costs have been rising even as the program has grown. In 2025, the average Medicare Advantage enrollee faces a maximum out-of-pocket limit of around $4,000 to $8,850 depending on plan type, and in markets dominated by a single hospital system, plans have less ability to negotiate those costs down.

For beneficiaries trying to navigate this landscape practically, the choices you make during enrollment windows matter enormously. If you're on Original Medicare without a supplement, you have no cap on hospital costs — a long inpatient stay could cost you tens of thousands of dollars out of pocket. A Medigap Plan G, the most popular supplement sold to new Medicare enrollees since 2020, covers the Part A deductible, all Part A coinsurance, and the 20% Part B coinsurance after you meet the $257 Part B deductible. In 2025, Plan G premiums typically range from about $100 to $200 per month depending on your age, gender, location, and the insurer — but that predictable monthly cost can be far less than a single unplanned hospitalization without coverage. You can compare Medigap plans at Medicare.gov's plan finder tool or by calling 1-800-MEDICARE.

If you're considering switching Medigap plans, timing matters. Outside of your initial enrollment window — which opens when you first enroll in Part B — insurers in most states can use medical underwriting to deny you coverage or charge higher premiums based on your health history. However, 13 states have enacted 'birthday rules' that give you a 30-day window each year around your birthday to switch Medigap plans without medical underwriting: California, Idaho, Illinois, Kentucky, Louisiana, Maine, Maryland, Missouri, Nevada, New Jersey, New York, Oklahoma, and Oregon. If you live in one of these states and your current Medigap plan has become expensive, your birthday window may be your best opportunity to shop for a lower premium on equivalent coverage.

For those enrolled in Medicare Advantage, the Annual Enrollment Period running October 15 through December 7 each year is your primary window to switch plans. The Open Enrollment Period from January 1 through March 31 allows one additional switch from a Medicare Advantage plan back to Original Medicare or to a different Medicare Advantage plan. When evaluating plans in a consolidated hospital market, pay close attention to whether your preferred hospital system is in-network, what the plan's maximum out-of-pocket limit is, and whether the plan uses prior authorization requirements that could delay care at high-cost facilities. A plan with a $0 premium but an $8,000 out-of-pocket maximum in a market where the dominant hospital charges top dollar may cost you far more than a plan with a modest premium and a $3,500 cap.

The broader policy debate over hospital consolidation and site-neutral payments will continue in Congress for years. But you don't have to wait for Washington to act. Choosing the right supplement or Medicare Advantage plan, understanding how hospital ownership affects your costs, and using your enrollment windows strategically are all things you can do right now to reduce your exposure to a system that has, for too long, been structured to benefit large health systems more than the patients they serve.