Medicare Advantage typically costs less in monthly premiums than Original Medicare, but whether it’s actually cheaper depends on how much care you use and where you get it. The upfront savings are real: the total average premium for a Medicare Advantage plan with drug coverage is just $13 per month in 2025, while Original Medicare’s Part B premium alone is $185 per month. But premiums only tell part of the story. Copays, network restrictions, and claim denials can shift the math significantly once you start using your coverage.
How Monthly Premiums Compare
With Original Medicare in 2025, every enrollee pays the standard Part B premium of $185 per month (higher earners pay more). On top of that, if you want prescription drug coverage, a standalone Part D plan averages $39 per month. That puts the baseline monthly cost at roughly $224 before you’ve seen a single doctor.
Medicare Advantage plans bundle all of this together, and many charge no additional premium beyond the Part B payment you’re already required to make. The average monthly premium for drug coverage within a Medicare Advantage plan is just $7, compared to $39 for a standalone Part D plan. That gap exists because Advantage plan sponsors can use federal rebate dollars to subsidize their drug coverage, something standalone drug plans can’t do. For someone choosing between the two on premium alone, Advantage saves well over $300 a year in drug coverage costs.
Many people also add a Medigap (Medicare Supplement) policy to Original Medicare to cover the 20% coinsurance and deductibles that Part B leaves behind. Medigap premiums vary widely by location, age, and insurer, but Plan G, the most popular option, commonly runs $150 to $300 or more per month. Adding that to Part B and Part D means Original Medicare with full gap coverage can easily cost $400 to $500+ per month. A Medicare Advantage plan with a $0 premium replaces all of that with just the $185 Part B payment.
What You Get for Less
Medicare Advantage plans frequently include benefits that Original Medicare doesn’t cover at all. Nearly all enrollees (99%) have access to eye exams or glasses, 98% get some dental coverage, 95% have hearing exams or hearing aids, and 94% get a fitness benefit. Under Original Medicare, you’d pay entirely out of pocket for most dental, vision, and hearing care unless you purchased separate policies.
These extras come with limits, though. Plans vary in how much they’ll actually pay toward covered services, and many impose annual dollar caps on dental or vision benefits. A plan might cover two cleanings and an exam but cap total dental spending at $1,000 or $1,500 a year. If you need a crown, implant, or hearing aids, you could still face large bills. The benefit is real but narrower than it looks in the plan brochure.
Where Advantage Can Cost More
The premium savings in Medicare Advantage come with tradeoffs that can make it more expensive for people who need significant care. The biggest difference is how each system handles claims.
Medicare Advantage plans deny about 17.7% of initial claims, roughly double the 8% denial rate providers report for Original Medicare. Prior authorization requirements, which barely exist in Original Medicare, are a major driver of that gap. When claims are denied, about 60% get resubmitted, and two-thirds of those resubmissions are eventually approved. But the process creates delays, and not every denial gets challenged. Providers end up losing about 7.2% of the total dollars they bill to Advantage plans after accounting for overturned denials. For you as a patient, that can mean delayed procedures, appeals paperwork, and out-of-pocket costs for care that Original Medicare would have covered without question.
Network restrictions add another layer. Most Medicare Advantage plans are HMOs or PPOs that require you to use specific doctors and hospitals. If you see an out-of-network provider, you may pay significantly more or get no coverage at all. Original Medicare lets you see any doctor in the country who accepts Medicare, which is the vast majority of physicians.
The Cost Picture for Serious Illness
One of the most revealing data points comes from people who leave Medicare Advantage and switch back to Original Medicare. A KFF analysis of 2022 data found that Medicare spending was 27% higher, on average, for people who disenrolled from Advantage compared to similar beneficiaries who stayed in traditional Medicare. The gap varied by condition: 15% higher for people with pneumonia, 28% higher (about $4,907 more) for people with certain cancers, and 34% higher for people with diabetes.
This pattern suggests that when health needs become complex, some people find Advantage plans harder or more costly to navigate, prompting them to switch back to Original Medicare at a point when their care needs (and costs) are already elevated. It doesn’t mean Advantage caused their costs to rise, but it does indicate that the savings picture can reverse for people managing serious or multiple chronic conditions.
Original Medicare has no out-of-pocket maximum on its own, which is a genuine financial risk. A long hospital stay or cancer treatment can generate enormous coinsurance bills with no cap. Medicare Advantage plans are required to set an annual out-of-pocket limit, giving you a ceiling on what you’ll spend each year. That ceiling provides protection Original Medicare lacks, unless you buy a Medigap policy to fill the gaps.
Comparing Total Annual Costs
For a healthy person who rarely sees doctors, Medicare Advantage is almost always cheaper. You avoid Medigap premiums, pay little or nothing beyond Part B, and get dental and vision coverage included. Your total annual cost might be just the $2,220 in Part B premiums plus the $257 Part B deductible, with minimal copays.
For someone with moderate health needs, the comparison gets closer. Original Medicare with a Medigap Plan G policy and standalone Part D coverage might run $5,000 to $8,000 a year in premiums alone, but your actual medical costs are almost entirely covered. With Advantage, your premiums are lower, but copays for specialist visits, imaging, hospital stays, and procedures add up. If you hit a string of health problems in one year, you could reach your plan’s out-of-pocket maximum.
For someone with complex or chronic health conditions, the answer depends on factors that are hard to predict in advance: whether your doctors are in network, whether your plan approves the treatments your providers recommend, and how much you’d spend in copays versus what you’d save in premiums. The prior authorization process becomes a bigger factor when you need frequent specialist care, advanced imaging, or expensive medications.
The Switch Can Be a One-Way Door
One detail that catches many people off guard: if you enroll in Medicare Advantage and later want to switch back to Original Medicare with a Medigap policy, you may not be able to get one at an affordable price. Outside of your initial Medigap open enrollment period (the six months after you turn 65 and enroll in Part B), insurance companies in most states can use medical underwriting. That means they can charge higher premiums or deny you a Medigap policy based on your health history. A few states have stronger consumer protections, but in most of the country, leaving Advantage after a few years locks you into Original Medicare without supplemental coverage unless you’re healthy enough to pass underwriting.
This makes the initial choice more consequential than it appears. Medicare Advantage may save you money for years, but if your health changes and you want the broader provider access of Original Medicare, the cost of switching back could be steep, or the option might not be available at all.