You worked 35 years, paid into the system, and you’re finally on Medicare. You assume you’re covered. Then you spend three days in the hospital, and a bill for $1,600 arrives — just for the deductible. Then another for 20% of the specialist’s fee. Then another for the outpatient procedure Medicare only partially paid for.
This happens to thousands of retirees every year who didn’t realize that Medicare — as good as it is — has significant gaps. The financial damage from those gaps can be catastrophic if you’re not prepared. This guide explains exactly what Medicare leaves uncovered, how much it can actually cost you, and the most effective ways to protect yourself in 2026.
What Medicare Actually Covers (And What It Doesn’t)
Medicare has four parts, and understanding what each covers is essential to understanding where the gaps are:
| Medicare Part | What It Covers | What You Pay (2026) |
|---|---|---|
| Part A (Hospital Insurance) | Inpatient hospital stays, skilled nursing facility (limited), hospice, some home health | $1,676 deductible per benefit period; $419/day for days 61–90; $838/day for lifetime reserve days |
| Part B (Medical Insurance) | Doctor visits, outpatient care, preventive services, medical equipment | $240/year deductible; then 20% of all approved costs — with NO OUT-OF-POCKET MAXIMUM |
| Part C (Medicare Advantage) | Alternative to Original Medicare; provided by private insurers; often includes Part D | Varies by plan; usually has copays and network restrictions |
| Part D (Prescription Drugs) | Prescription medications | Varies by plan; premiums typically $20–$100/month |
The Biggest Gap: No Out-of-Pocket Maximum Under Original Medicare
Here’s the number that shocks most people: Original Medicare (Parts A and B) has no cap on your out-of-pocket costs. If you’re seriously ill — a major surgery, a cancer diagnosis, a stroke — Medicare pays 80% of approved costs, and you owe 20%. On a $200,000 hospital bill, that’s $40,000 out of pocket. And it doesn’t stop there.
The 20% coinsurance under Part B applies to every doctor visit, every specialist, every outpatient procedure — with no annual limit on what you pay. This is the exposure that sends people into financial crisis even when they have Medicare.
What Medicare Specifically Does NOT Cover
Beyond the cost-sharing gaps, Medicare flat-out excludes entire categories of care that seniors commonly need:
- Long-term care / custodial care — Medicare does not pay for assisted living, nursing home care for daily activities, or in-home personal care. This is the single most dangerous coverage gap for retirees.
- Dental care — Original Medicare does not cover routine dental, cleanings, fillings, extractions, or dentures. Medicare Advantage plans often include some dental benefits.
- Vision care — Routine eye exams and eyeglasses are not covered. Medicare covers eye exams only for specific medical conditions like glaucoma or diabetic retinopathy.
- Hearing aids — Not covered. Hearing aids average $4,000–$7,000 per pair. Medicare does not pay a dollar toward them.
- Overseas medical care — Medicare does not cover healthcare outside the US (with very limited exceptions). If you travel internationally, you need separate coverage.
- Most prescription drugs — Part A and B don’t cover most prescriptions; Part D must be purchased separately.
- Cosmetic procedures — Not covered (expected, but worth noting)
How Much Can the Gaps Actually Cost You?
These scenarios show the real financial risk of relying on Medicare alone:
| Medical Situation | Total Bill | Medicare Pays | You Owe (No Supplement) |
|---|---|---|---|
| 3-day hospital stay | $30,000 | ~$28,324 | ~$1,676 (Part A deductible) |
| Heart bypass surgery | $150,000 | ~$120,000 | ~$30,000+ (20% coinsurance) |
| Cancer treatment (1 year) | $200,000+ | 80% of approved costs | $40,000+ with NO cap |
| Skilled nursing (60 days) | ~$20,000 | Days 1–20 fully; Days 21–60 minus $209.50/day | ~$5,040 for days 21–60 |
| Skilled nursing (100+ days) | $33,000+ | $0 after day 100 | 100% of costs after day 100 |
These are not worst-case scenarios — they’re typical costs for common medical events that become more likely with age. For the average Medicare beneficiary, the out-of-pocket exposure under Original Medicare alone is tens of thousands of dollars per serious illness episode.
The Two Ways to Fill the Gaps: Medigap vs Medicare Advantage
There are two main approaches to covering Medicare’s gaps. Understanding which is right for you is one of the most important financial decisions of retirement.
Option 1: Medicare Supplement Insurance (Medigap)
Medigap policies are sold by private insurance companies and work alongside Original Medicare. Medicare pays first; Medigap pays some or all of what’s left. There are 10 standardized plan types (A through N), each covering a specific set of gaps.
| Plan | Part A Coinsurance | Part B Coinsurance | Part A Deductible | Out-of-Pocket Limit | Foreign Travel Emergency |
|---|---|---|---|---|---|
| Plan G (most popular) | 100% | 100% | 100% | N/A (very comprehensive) | 80% |
| Plan N | 100% | 100% (some copays) | 100% | N/A | 80% |
| Plan K | 50% | 50% | 50% | $7,220 (2026) | No |
| Plan L | 75% | 75% | 75% | $3,610 (2026) | No |
Plan G is the most popular Medigap plan in 2026. It covers nearly everything except the Part B deductible ($240/year). After you pay that $240, Plan G covers 100% of your Medicare-approved costs — no surprise bills, no 20% coinsurance. Monthly premiums for Plan G average $100–$200/month depending on age, location, and insurer.
Advantages of Medigap:
- Use any doctor or hospital that accepts Medicare — no networks
- Predictable monthly cost; no surprise bills for covered services
- Renewable for life (insurer can’t drop you for getting sick)
- Works the same everywhere in the US
Disadvantages:
- Monthly premium on top of Part B premium
- Does not include prescription drug coverage (need separate Part D)
- Does not include dental, vision, or hearing
- Medical underwriting if you enroll outside Open Enrollment (you can be denied or charged more)
Option 2: Medicare Advantage (Part C)
Medicare Advantage plans replace Original Medicare through a private insurer. You pay the plan’s copays and deductibles instead of Medicare’s. Many plans include extras like dental, vision, hearing, and prescription drug coverage — sometimes for no extra premium beyond your Part B payment.
Advantages of Medicare Advantage:
- Often lower (or $0) monthly premium beyond Part B
- May include dental, vision, and hearing
- Has an annual out-of-pocket maximum (unlike Original Medicare)
- Typically includes Part D prescription coverage
Disadvantages:
- Network restrictions — you must use in-network providers
- Prior authorization required for many procedures
- Coverage can change year to year
- Out-of-pocket maximums can be $8,000+ — still significant
- May be problematic if you travel frequently or split time between states
Medigap vs Medicare Advantage: Which Is Right for You?
| Your Situation | Better Choice |
|---|---|
| You have complex medical needs or see specialists frequently | Medigap (no network restrictions, predictable costs) |
| You’re healthy and cost-conscious with a limited budget | Medicare Advantage (lower or $0 premium) |
| You travel internationally or between states | Medigap (works nationwide; Advantage is often region-specific) |
| You want dental/vision included | Medicare Advantage (most include these extras) |
| You want maximum financial protection | Medigap Plan G (most comprehensive coverage) |
| You live in a rural area with limited providers | Medigap (Medicare Advantage networks may be thin in rural areas) |
When to Enroll: The Window You Cannot Miss
The most important thing to know about Medigap: your Medigap Open Enrollment Period begins the month you turn 65 and are enrolled in Part B. During this 6-month window, insurers must sell you any Medigap plan at standard rates — they cannot deny you based on health or charge you more for pre-existing conditions.
After this window closes, you can generally only switch Medigap plans through medical underwriting. If you’ve developed health conditions, you may be denied or charged significantly higher premiums. This is one of the most costly mistakes retirees make — delaying Medigap enrollment and then being unable to get comprehensive coverage later when they actually need it.
How to Choose the Best Medigap Plan
- Identify your priority: Maximum coverage (Plan G) vs lower premium with some cost-sharing (Plan N or K)
- Get quotes from multiple insurers: All insurers sell the same standardized plans, but premiums vary significantly. Use Medicare.gov’s plan finder or work with an independent broker.
- Check premium increase history: Some insurers raise rates aggressively as you age. Ask for the past 5 years of rate increases before choosing.
- Consider “attained-age” vs “issue-age” vs “community-rated” plans: How the premium is structured affects how much it increases as you get older.
- Don’t skip Part D: Add a stand-alone prescription drug plan alongside your Medigap policy. Waiting too long has late enrollment penalties.
The Long-Term Care Gap: The Biggest Threat to Retirement Savings
Medigap solves the Medicare cost-sharing problem. But there’s a much bigger gap that Medigap, Medicare, and Medicare Advantage all ignore: long-term care.
The statistics are sobering: 70% of Americans who reach age 65 will need some form of long-term care. The average assisted living cost is $4,995/month in 2026. Nursing home care averages $8,669/month for a semi-private room. Medicare covers a maximum of 100 days of skilled nursing care per benefit period — and only when it follows a qualifying 3-day hospital stay. After that, you’re on your own.
The options for long-term care protection include long-term care insurance (purchased before you need it), hybrid life/LTC policies, or self-funding through savings. This is a separate planning challenge from Medicare gaps — but it’s just as important.
Frequently Asked Questions
How much does Medigap Plan G cost in 2026?
Plan G premiums in 2026 typically range from $100–$200 per month for a 65-year-old depending on location, gender, and the insurer. The same plan from different companies can vary by $50–$80/month — which is why comparing quotes matters. Some high-cost-of-living states like California, New York, and Massachusetts have higher premiums.
Can I switch from Medicare Advantage back to Original Medicare?
Yes. You can switch during the Annual Enrollment Period (October 15 – December 7) or the Medicare Advantage Open Enrollment Period (January 1 – March 31). However, if you want to add Medigap after switching back to Original Medicare, you may face medical underwriting in most states — meaning your health could affect whether you qualify.
Is Medigap worth it?
For most people, yes — especially if you have ongoing health conditions, see doctors regularly, or want peace of mind that a serious illness won’t create financial catastrophe. The math typically favors Medigap Plan G for anyone who has even one significant medical event per year. For very healthy seniors who rarely use medical care, Medicare Advantage with a lower premium might be more cost-effective — until a major illness hits.
What’s the difference between Medigap Plan F and Plan G?
Plan F covers the Part B deductible ($240 in 2026); Plan G does not. Plan F is no longer available to people who became Medicare-eligible after January 1, 2020. For those who were eligible before 2020 and have Plan F, it’s often worth keeping. For everyone else, Plan G is the most comprehensive available option — and typically cheaper in net cost than Plan F was.
The Bottom Line
Medicare is a remarkable benefit — but assuming it covers everything is a costly mistake that catches thousands of retirees off guard every year. The gaps are real, the costs are substantial, and a major illness without supplemental coverage can damage or destroy a retirement nest egg built over decades.
The solution is straightforward: during your Medigap Open Enrollment window, compare Plan G and Plan N from multiple insurers and choose a policy that fits your budget. If you’re already past that window or on Medicare Advantage, understand your current out-of-pocket exposure and make sure you’re not one serious illness away from a financial crisis.
Don’t wait until you need it to figure this out. The time to protect yourself from Medicare’s gaps is before you end up in the hospital learning about them for the first time.