What Medicare doesn’t cover — and how to fill the gaps
New retirees are often shocked to learn that “Medicare” and “full coverage” are not the same thing. Original Medicare leaves four big holes — dental, vision, hearing, and long-term care — and, more dangerously, has no cap on your out-of-pocket costs. None of that means Medicare is bad; it means Medicare needs a plan around it. Here’s every major gap, what each one realistically costs, how to fill it — and the reason federal retirees start with a built-in advantage most Americans don’t have.
1. The “full coverage” myth
Most people spend their working years inside employer health plans that quietly cover dental cleanings, eye exams, and a yearly out-of-pocket ceiling. Then they turn 65, enroll in Medicare, and assume the same protections carry over. They don’t. Medicare was built in 1965 around hospital and physician care, and many of those original exclusions remain unchanged today.
The fix isn’t to distrust Medicare — it’s to know exactly where the holes are before a bill finds them for you. There are four big gaps and a handful of smaller ones. Walk through each, attach a realistic price, and you can close every one with the right supplemental coverage.
2. The big three: dental, vision, hearing
The most common surprises are the everyday services people use most. Original Medicare pays nothing for routine dental, vision, or hearing care — and neither does a Medigap policy. The bills land entirely on you:
| Service | Typical out-of-pocket cost |
|---|---|
| Routine cleaning & exam | $200–$350 |
| Dental crown | $1,000–$1,700 |
| Dentures (per arch) | $1,500–$3,500 |
| Dental implant | $3,000–$6,000 |
| Eye exam + progressive lenses & frames | $400–$950 |
| A pair of hearing aids | $2,000–$6,000 |
A single year that brings two hearing aids, a crown, and new glasses can easily top $6,000 in costs neither Medicare nor Medigap will touch — and across a 20-to-30-year retirement, that recurring exposure adds up to real money. No legislation has added these benefits to Original Medicare, so for 2026 the options remain supplemental.
3. The no-cap problem
This is the gap that does the most financial damage precisely because it’s invisible until a serious illness. After the $283 Part B deductible (2026), Original Medicare pays 80% of most outpatient services and you pay the other 20% — with no annual out-of-pocket maximum. In a year with cancer treatment, major surgery, or a long course of specialty care, that uncapped 20% can run into tens of thousands of dollars.
Every other form of health coverage you’ve had — employer plans, ACA plans, FEHB — includes an out-of-pocket ceiling. Original Medicare alone does not. That single feature is the strongest argument for pairing Medicare with something that does cap your exposure, whether a Medigap policy, a Medicare Advantage plan, or, for federal retirees, FEHB.
Dental and hearing costs are predictable and budgetable. The uncapped 20% is the one that can produce a five-figure surprise in a single bad year. Closing it should be the first priority, not the last.
4. Long-term care: the biggest gap
The most dangerous misconception in retirement is that Medicare covers long-term care. It does not. Medicare pays for short skilled-nursing stays — up to 100 days following a qualifying 3-day inpatient hospital stay, and only for skilled care like rehabilitation. In 2026 you owe a $217-per-day coinsurance for days 21–100, and after day 100 Medicare coverage ends entirely.
What Medicare never covers is custodial care — the everyday help with bathing, dressing, eating, and moving that makes up the vast majority of long-term care. With nursing homes running roughly $115,000 a year and assisted living about $74,000, this is the gap with the power to erase a retirement. It’s large enough to deserve its own playbook — see our guide on long-term care costs and planning.
5. The other exclusions
Beyond the big four, a handful of smaller but important gaps round out the list:
- Prescription drugs. Parts A and B don’t cover most outpatient medications — that’s what a separate Part D plan is for (good news for 2026: Part D now caps your out-of-pocket drug spending at $2,100).
- Care overseas. Original Medicare generally pays nothing outside the U.S., a critical gap for retirees who travel or live abroad.
- Routine foot care and most cosmetic surgery are excluded.
- Acupuncture is covered only in narrow circumstances (chronic low-back pain).
Each is fillable, but only if you know it’s there. The drug gap is closed with Part D; the overseas gap with FEHB or travel medical coverage; the rest with supplemental plans or out-of-pocket budgeting.
6. Estimate your annual gap
Plug in your realistic yearly costs for the services Medicare skips, plus your expected Part B charges, and the calculator totals the out-of-pocket exposure Original Medicare leaves open — the number a supplement is designed to close.
Your gap costs
The 20% coinsurance shown has no annual cap under Original Medicare — in a high-cost year it can be far larger. A Medigap or FEHB plan would cover most of it. Estimates only, not advice.
7. How to fill each gap
Every gap has a fix; the trick is matching the right tool to the right hole without double-paying:
| Gap | How to close it |
|---|---|
| The uncapped 20% | Medigap (Supplement), Medicare Advantage’s required cap, or FEHB coordinating with Medicare |
| Dental / vision / hearing | FEDVIP (federal), Advantage extras, or standalone dental/vision policies |
| Prescription drugs | A standalone Part D plan, or drug coverage bundled in Advantage / FEHB |
| Long-term care | LTC insurance, personal savings, or Medicaid after spend-down |
| Overseas care | FEHB (covers worldwide) or travel medical insurance |
A core decision sits underneath this table: Medigap versus Medicare Advantage. Medigap plus a Part D plan gives you broad provider freedom and predictable costs at a higher premium; Advantage bundles extras and an out-of-pocket cap but adds networks and prior authorization. We compare them head-to-head in Medicare vs. Medicare Advantage.
8. The federal advantage
Here’s where federal retirees pull ahead of nearly everyone else. You can keep your FEHB coverage in retirement and pair it with Medicare — and FEHB quietly fills most of the gaps above. FEHB plans carry their own annual out-of-pocket maximum, so the dreaded uncapped 20% is already covered. When FEHB coordinates with Medicare as your secondary payer, it often waives much of your cost-sharing, functioning much like a Medigap policy you didn’t have to buy separately.
On top of that, federal retirees can enroll in FEDVIP dental and vision plans to address the “big three,” and FEHB’s worldwide coverage closes the overseas gap. This is exactly why many federal retirees skip a standalone Medigap policy: their FEHB plan already does the job. The open questions for feds become which FEHB plan to keep and whether to take Part B — decisions we walk through in the Part B decision guide. The one gap FEHB doesn’t solve is long-term care, which still needs its own plan.
9. Frequently asked questions
What does Original Medicare not cover?
Original Medicare (Parts A and B) excludes several major categories. The “big three” are routine dental, vision, and hearing care — no cleanings, fillings, dentures, eye exams, glasses, or hearing aids. It also doesn’t cover long-term custodial care, most care received overseas, routine foot care, or cosmetic surgery. Outpatient prescription drugs are excluded from A and B; you get those through a separate Part D plan. And crucially, Original Medicare has no annual out-of-pocket maximum, so your 20% share of Part B costs has no ceiling.
Does Medicare cover dental, vision, and hearing?
No — routine dental, vision, and hearing care are the most common surprises for new beneficiaries. Original Medicare won’t pay for cleanings, fillings, crowns, dentures, routine eye exams, eyeglasses, or hearing aids. Medigap doesn’t cover them either. To get these benefits you generally need a Medicare Advantage plan that bundles them, standalone dental and vision policies, or — for federal retirees — your FEHB plan and FEDVIP dental/vision coverage, which can carry into retirement alongside Medicare.
Does Medicare have an out-of-pocket maximum?
Original Medicare has no annual out-of-pocket maximum. You pay the Part B deductible ($283 in 2026) and then 20% coinsurance on most Part B services, with no cap on how high that 20% can climb in a serious year. This is one of the biggest and least understood gaps. The two ways to limit the exposure are a Medigap (Medicare Supplement) policy, which covers much of the 20%, or a Medicare Advantage plan, which by law must include an annual out-of-pocket maximum. For federal retirees, keeping FEHB alongside Medicare also caps exposure, since FEHB plans have their own out-of-pocket limits.
Does Medicare cover long-term care?
Almost never. Medicare covers short skilled-nursing stays — up to 100 days following a qualifying 3-day inpatient hospital stay, and only for skilled care like rehab or wound care. It does not cover custodial long-term care, which is the everyday help with bathing, dressing, eating, and moving that makes up the vast majority of long-term care. That’s the single largest gap in Medicare, and filling it requires separate long-term care insurance, personal savings, or, after a spend-down, Medicaid. Our long-term care planning guide covers the options in detail.
How do federal retirees fill Medicare’s gaps?
Federal retirees have a major advantage: they can keep their FEHB coverage in retirement and pair it with Medicare. FEHB plans have their own out-of-pocket maximums and often cover services Original Medicare skips, and when FEHB coordinates with Medicare it can act much like a Medigap policy, frequently waiving cost-sharing. Federal retirees can also enroll in FEDVIP dental and vision plans to address the “big three” gaps. This combination is why many federal retirees don’t buy a separate Medigap policy — their FEHB plan already fills most of the holes.
- Medicare.gov, “What’s Not Covered by Part A & Part B”
- CMS, “2026 Medicare Part B Premiums and Deductibles”
- NCOA, “What Medicare Covers for Dental, Vision, and Hearing”
- Medicare.gov, “Medicare Costs” (no out-of-pocket cap)
- OPM, “FEHB and Medicare” coordination
- BENEFEDS, FEDVIP dental and vision enrollment