Most retirees assume Medicare covers nearly everything. The reality—and the numbers—tell a very different story.

There’s a moment that catches many new retirees off guard. They’ve done the math, set up their budget, and feel genuinely confident heading into retirement. Then the Medicare bills start arriving—and the numbers don’t match what they expected.

It’s not that Medicare is a bad deal. For most retirees, it’s an essential financial lifeline. But the gap between what people think Medicare covers and what it actually covers is wide enough to derail an otherwise solid retirement plan. Fidelity Investments estimates that the average couple retiring today will need around $315,000 set aside just to cover healthcare costs in retirement—and that figure doesn’t include long-term care.

The retirees who navigate Medicare successfully aren’t the ones with the most money. They’re the ones who saw these costs coming and planned for them. This article is your heads-up.

Hidden Cost #1: Your Part B Premium (Which Goes Up Every Year)

Most people know Medicare has a monthly premium for Part B—the portion that covers doctor visits, outpatient services, and preventive care. What surprises many retirees is how much it is and how automatically it gets deducted.

In 2025, the standard Part B premium is $185 per month per person. For a married couple, that’s $370 every single month—or $4,440 per year—coming straight out of your Social Security check before you ever see it.

And that’s just the standard rate. If your income in retirement is higher than certain thresholds, you’ll pay significantly more through a surcharge called IRMAA (more on that shortly).

How to budget for it: Don’t think of Part B as a future expense—think of it as a permanent reduction to your Social Security income starting at 65. Build your retirement budget around your net Social Security amount, not the gross figure.

Hidden Cost #2: IRMAA—The High-Income Surcharge Nobody Warns You About

IRMAA stands for Income-Related Monthly Adjustment Amount, and it is one of the most unpleasant surprises a retiree can encounter.

Here’s how it works: Medicare looks at your tax return from two years prior to set your current premium. If your income was above $106,000 (individual) or $212,000 (joint) in that prior year, you’ll pay a higher Part B premium—sometimes dramatically higher.

The surcharges climb in tiers. At the highest income levels, Part B alone can cost over $628 per month per person. And IRMAA applies to Part D (prescription drug coverage) as well, stacking the additional charge further.

What makes IRMAA especially painful is its timing. A retiree who sold a rental property or did a large Roth conversion in their last working year might trigger IRMAA two years later—at exactly the moment they assumed their income was lower and their costs were stable.

How to budget for it: If you anticipate any large income events in the years before Medicare eligibility, talk to a tax advisor or financial planner about IRMAA exposure before the transaction, not after. There is an appeals process if your income has since dropped significantly, and it’s worth using.

Hidden Cost #3: The Part B Deductible and 20% Coinsurance

Even after paying your monthly premium, Medicare Part B doesn’t cover everything. You’re also responsible for an annual deductible — $257 in 2025 — and then, once that’s met, Medicare typically covers 80% of approved costs. That means you cover 20%.

For routine visits and minor procedures, that 20% is manageable. But for a major health event — a cancer diagnosis, a cardiac procedure, a serious accident — 20% of a large medical bill can mean thousands or tens of thousands of dollars out of pocket, with no annual cap under original Medicare.

This is exactly why most financial advisors recommend pairing original Medicare with either a Medigap (Medicare Supplement) policy or enrolling in a Medicare Advantage plan, which typically has its own out-of-pocket maximum. Neither option is free, but both put a ceiling on your exposure.

How to budget for it: Factor in either a Medigap premium (typically $100–$300/month depending on plan and age) or research Medicare Advantage plans in your area during open enrollment. Compare total out-of-pocket maximums, not just monthly premiums.

Hidden Cost #4: Prescription Drug Coverage Has Real Gaps

Medicare Part D covers prescription drugs, but the coverage has historically had significant gaps that could leave retirees paying substantial amounts for certain medications.

The good news: the Inflation Reduction Act introduced a $2,000 annual out-of-pocket cap for Part D starting in 2025, which is a meaningful improvement for retirees on expensive medications. Before 2025, there was no hard cap, and costs could spiral much higher.

The not-so-good news: Part D plans vary widely in what they cover and what they charge. Two plans in the same ZIP code can have very different formularies—the list of covered drugs—meaning a medication covered at low cost under one plan may not be covered at all under another.

How to budget for it: Don’t auto-renew your Part D plan each year. Use Medicare’s Plan Finder tool (medicare.gov) during open enrollment to compare plans based on your specific list of medications. The cheapest premium is rarely the cheapest total cost.

Hidden Cost #5: Dental, Vision, and Hearing—The Big Three Gaps

This is the one that genuinely shocks most new Medicare enrollees: original Medicare does not cover routine dental, vision, or hearing care.

No annual cleanings. No fillings. No eyeglasses. No hearing aids.

For retirees, this is a significant exposure. Dental care becomes more complex and expensive with age. Hearing loss affects roughly two-thirds of adults over 70. Vision care is ongoing. These aren’t optional luxuries—they’re core health needs.

Out-of-pocket dental costs in retirement can be brutal. A single crown can cost $1,000–$2,000. Dentures can run $3,000–$6,000 or more. Hearing aids typically cost $4,000–$6,000 per pair and need replacement every few years.

Some Medicare Advantage plans include limited dental, vision, and hearing benefits, which is one reason these plans have grown so popular. Standalone dental and vision insurance is also available, though premiums and benefit limits vary widely.

How to budget for it: Set aside a dedicated dental and vision reserve—a separate savings bucket—rather than hoping costs won’t arise. A reasonable starting point is $1,500–$2,500 per year per person, more if you have existing dental issues. Get a full dental assessment before your Medicare coverage begins, while you may still have employer dental coverage.

Hidden Cost #6: Long-Term Care—The Cost That Can Erase a Retirement

Medicare covers short-term skilled nursing care under specific conditions—and nothing else when it comes to long-term care. It does not pay for assisted living. It does not pay for in-home care if you need help with daily activities. It does not pay for memory care.

Medicaid does cover long-term care for those who qualify financially—but qualifying typically means spending down most of your assets first.

The numbers for long-term care are significant. According to Genworth’s Cost of Care survey, the median annual cost for a private room in a nursing home exceeds $100,000. Assisted living averages around $64,000 per year. In-home care with a home health aide runs $30–$35 per hour.

The average person who needs long-term care requires it for about three years, though the range is wide and unpredictable. For couples, the risk of at least one partner needing extended care is substantial.

How to budget for it: Long-term care insurance is one option, though premiums have risen significantly and insurers have exited the market. Hybrid life insurance policies with long-term care riders are a more flexible alternative. At minimum, have an honest conversation with a financial planner about your long-term care strategy before you need one.

Putting It All Together: A Simple Medicare Budget Framework

Here’s a practical framework for estimating your annual Medicare-related costs:

For a couple, these numbers double. The range is wide, which is exactly why planning—and not assuming—is so important.

The Bottom Line

Medicare is a remarkable resource, and for most retirees, it provides real, meaningful coverage. But it is not free, and it is not complete. The retirees who build the most financially secure retirements are the ones who go in with eyes open—who know the gaps, plan for the costs, and make deliberate decisions about how to cover what Medicare doesn’t.

The worst time to discover these costs is after they’ve arrived. The best time is right now.

You might also want to read: Medicare Explained: Parts A, B, C, & D Simplified for Beginners

The information in this article is provided for general educational purposes only and is not a substitute for personalized financial or medical advice. Medicare rules and costs are updated annually. Always verify current figures at medicare.gov or consult a licensed Medicare advisor.