No single Medicare supplement covers everything, but some come closer than others
Medicare supplement insurance (also called Medigap) fills gaps in Original Medicare — the deductibles, copayments, and coinsurance you'd otherwise pay out of pocket. But no Medigap plan covers prescription drugs, dental, vision, hearing aids, or long-term care. Plan G and Plan N cover the most of what Original Medicare leaves behind, but even they have limits. The "best" plan depends on what you actually use and what you can afford to pay in premiums.
The federal government standardizes Medigap plans, so Plan G from one insurance company covers exactly the same things as Plan G from another. What changes is the monthly premium you pay. This means you can compare plans by their coverage first, then shop by price.
Key Takeaways
- Plan G and Plan N cover the most hospital and doctor costs, but neither covers prescription drugs, dental, vision, or hearing aids.
- All Medigap plans are standardized by the federal government, so the coverage is identical across insurers — only the monthly premium differs.
- You can enroll in a Medigap plan during your initial enrollment period (the six months after you turn 65 and sign up for Part B) without medical underwriting in most states.
- Medicare Advantage (Part C) is an alternative to Original Medicare plus Medigap, and it often includes prescription drug, dental, and vision coverage in one plan.
What Plan G covers (the most comprehensive Medigap option)
Plan G pays your Part B deductible, coinsurance, and copayments. It covers the Part A hospital deductible, coinsurance for hospital stays beyond 60 days, and skilled nursing facility coinsurance. It also pays for excess charges — the amount a doctor can bill above Medicare's approved amount, up to 15 percent in most states. Plan G does not have a yearly out-of-pocket limit, so your costs depend on how much medical care you use.
Plan G became the most popular Medigap option in 2020 when the federal government stopped selling Plan F (which covered the Part B deductible) to people newly may be able to access for Medicare. If you enrolled in Plan F before 2020, you can keep it, but new enrollees cannot.
What Plan N covers (lower premiums, slightly more cost-sharing)
Plan N is less expensive than Plan G but requires you to pay a copayment at the doctor's office (usually $20) and at urgent care (usually $50). You also pay the Part B deductible yourself. Plan N covers hospital costs, skilled nursing facility coinsurance, and excess charges the same way Plan G does.
Plan N appeals to people who visit the doctor infrequently and want to lower their monthly premium. If you go to the doctor often, the copayments can add up and offset the savings on premiums.
What no Medigap plan covers
Prescription drugs: You need a separate Part D plan. You can enroll in Part D when you first sign up for Medicare, or during the annual open enrollment period (October 15 to December 7). If you delay Part D without creditable coverage, you may pay a penalty for as long as you have Medicare.
Dental, vision, and hearing: Original Medicare does not cover routine dental care, eye exams, eyeglasses, or hearing aids. Some Medigap insurers offer limited dental and vision riders for an extra monthly fee, but these are not standardized and vary widely. Medicare Advantage plans often include dental and vision as part of the base plan.
Long-term care: Neither Original Medicare nor Medigap pays for nursing home care, assisted living, or in-home care. You would pay out of pocket, use Medicaid (if you may have access to), or have purchased long-term care insurance before you needed it.
How Medigap enrollment works and when you have the best rates
You have a six-month window called your Medigap open enrollment period that starts the month you turn 65 and enroll in Medicare Part B. During this window, insurance companies cannot deny you coverage or charge more based on your health history — a protection called may provide issue. After this window closes, insurers can medically underwrite you, which means they can refuse to sell you a plan or charge higher premiums if you have pre-existing conditions.
If you miss your open enrollment window, you can still buy Medigap later, but you may face medical underwriting and higher costs. Some states have additional protections that extend may provide issue in certain situations, such as if you lose employer coverage or move out of state.
Medigap premiums vary by age, location, and the insurance company. The same Plan G might cost $100 a month in one state and $200 in another, or $120 at one company and $160 at another. You can compare plans and prices on Medicare.gov or by calling insurers directly.
Medicare Advantage as an alternative to Original Medicare plus Medigap
Instead of Original Medicare plus a Medigap plan, you can choose Medicare Advantage (Part C), which is a managed care plan run by a private insurance company. Medicare Advantage often includes prescription drug coverage, dental, vision, and hearing benefits in one monthly premium. Many plans have no premium beyond your Part B premium, though some charge a small monthly fee.
The trade-off is that Medicare Advantage plans have networks — you usually must use in-network doctors and hospitals, and you need a referral to see a specialist. Out-of-network care is often not covered except in emergencies. If you travel frequently or have doctors you want to keep, Original Medicare plus Medigap gives you more flexibility.
You can switch between Original Medicare and Medicare Advantage during the annual enrollment period (October 15 to December 7) or during the Medicare Advantage open enrollment period (January 1 to March 31). If you switch to Original Medicare after being on Medicare Advantage, you can buy a Medigap plan, but you may face medical underwriting unless you may have access to for may provide issue in your state.
Comparing your actual costs: premiums, deductibles, and copayments
The cheapest Medigap premium is not always the cheapest option overall. If you choose Plan N to save $30 a month on premiums but visit the doctor 10 times a year, you'll pay $200 in copayments annually — offsetting the savings. If you rarely see a doctor, Plan N's lower premium wins.
Write down the plans you're considering and estimate your annual costs: monthly premium × 12, plus your expected deductibles and copayments based on your health history. Add the cost of a Part D plan if you take prescription drugs. This gives you a realistic picture of what each option will cost you in a given year.
Keep in mind that premiums can increase each year, and your health needs may change. Some people switch plans annually during open enrollment to find the best rate for their situation.
Frequently Asked Questions
Can I switch from one Medigap plan to another?
Yes, you can switch between Medigap plans during the annual open enrollment period (October 15 to December 7). Outside this window, you may face medical underwriting. Some states allow switching without underwriting in certain situations, such as if your current plan is no longer sold in your area.
What happens if I don't buy a Medigap plan when I first turn 65?
You can buy one later, but you lose your may provide issue protection. Insurers can deny you coverage or charge higher premiums based on your health. Some states have limited may provide issue windows if you lose employer coverage or move, so check your state's rules.
Do I need both a Medigap plan and a Part D plan?
Yes, if you take prescription drugs. Medigap covers hospital and doctor costs; Part D covers medications. You enroll in Part D separately, usually when you first sign up for Medicare or during annual open enrollment.
Is Medicare Advantage cheaper than Original Medicare plus Medigap?
It depends on your situation. Medicare Advantage often has lower or no monthly premiums and includes dental and vision, but it limits you to a network of doctors and hospitals. Original Medicare plus Medigap costs more in premiums but gives you more flexibility to see any doctor who accepts Medicare.
What if I want dental or vision coverage?
Original Medicare and Medigap do not cover routine dental or vision care. Some Medigap insurers sell optional dental and vision riders, but coverage is limited and varies by company. Medicare Advantage plans often include more comprehensive dental and vision benefits as part of the base plan.