Medicare Part F covers most of your out-of-pocket costs after Original Medicare pays its share

Medicare Part F is a Medigap (supplemental insurance) plan sold by private insurance companies. It pays many of the costs that Original Medicare (Parts A and B) does not cover — copayments, coinsurance, and deductibles. Part F is the most comprehensive Medigap option available, which is why it tends to cost more than other Medigap plans.

Part F does not replace Original Medicare. You keep your Medicare card and use it at doctors and hospitals. Part F straightforward steps in after Medicare pays, covering what you would otherwise owe out of pocket.

Not everyone can buy Part F. New Medicare enrollees as of January 1, 2020, are not allowed to purchase it. If you enrolled in Medicare before that date, you can still buy Part F at any time, though the premium will be higher if you enroll after your initial enrollment window.

Key Takeaways

  • Part F covers the Part A deductible, Part B deductible, Part B copayments and coinsurance, and the cost of a second opinion before surgery.
  • Part F does not cover prescription drugs, dental care, vision care, hearing aids, or long-term care — you need separate coverage for those.
  • Part F premiums vary by insurance company and your age, and they increase each year.
  • You must have Original Medicare (Part A and Part B) to buy Part F; it cannot stand alone.
  • If you enrolled in Medicare before January 1, 2020, you can buy Part F; if you enrolled after that date, you cannot.

What Part F actually covers

Part F covers the Part A deductible — the amount you pay before Medicare hospital insurance kicks in. It also covers Part B coinsurance, which is the percentage of the cost you normally pay after Medicare pays its share (usually 20 percent). Part F pays that 20 percent for most services.

Part F also covers the Part B deductible, the yearly amount you must pay before Part B coverage begins. It covers the cost of a second surgical opinion if your doctor recommends surgery. And it covers excess charges — the amount some doctors charge above what Medicare allows, though fewer doctors use this option now.

Part F does not cover prescription drugs. You need Part D (prescription drug coverage) for that, and you buy it separately. Part F also does not cover dental, vision, hearing aids, or long-term care. Those are not covered by any standard Medigap plan.

How Part F premiums work

Part F premiums vary widely depending on which insurance company sells the plan and where you live. The same plan from different insurers can cost $100 to $300 per month or more. You pay the premium directly to the insurance company, not to Medicare.

Premiums increase each year, usually in January. The increase depends on the insurer and may reflect your age, inflation, or claims experience. Some insurers use attained-age pricing, meaning your premium rises as you get older. Others use issue-age pricing, meaning the premium is based on your age when you first buy the plan and does not increase because of age alone.

If you enroll in Part F during your initial enrollment window (the six-month period that starts the month you turn 65 and enroll in Part B), insurers cannot deny you coverage or charge more based on your health. If you enroll after that window, some insurers may require medical underwriting, meaning they review your health history and can charge higher premiums or deny coverage.

Who can and cannot buy Part F

You can buy Part F only if you enrolled in Medicare before January 1, 2020. This rule was set by federal law. If you turned 65 on or after January 1, 2020, or if you enrolled in Medicare after that date for any reason, you cannot buy Part F, even if you are now older.

If you enrolled before January 1, 2020, you can buy Part F at any time — there is no important date. However, if you buy it outside your initial enrollment window, you may face higher premiums and medical underwriting.

You must have Original Medicare (Part A and Part B) to buy Part F. You cannot use Part F with Medicare Advantage (Part C). If you have Medicare Advantage and want to switch to Original Medicare plus Part F, you can do so during the annual open enrollment period (October 15 to December 7) or during a may have access to life event.

Part F versus other Medigap plans

Medigap comes in ten standardized plans: A, B, D, G, K, L, M, N, and high-deductible F and G. (Plans C and F are no longer sold to new enrollees, but people who bought them before January 1, 2020, can keep them.) Each plan covers a different set of costs.

Part F is the most comprehensive — it covers nearly everything Original Medicare does not. Plan G covers almost as much as Part F but does not cover the Part B deductible. Plans A, B, D, K, L, M, and N cover fewer costs but have lower premiums. The trade-off is that you pay more out of pocket when you use medical services.

High-deductible Plan F and high-deductible Plan G have much lower premiums but require you to pay a yearly deductible (around $2,700 in 2024, though this amount changes yearly) before the plan pays anything. These plans make sense only if you are healthy and do not expect to use many medical services.

How to buy Part F

You buy Part F directly from a private insurance company, not from Medicare. You can contact insurers by phone or visit their websites. Some common insurers that sell Medigap plans include AARP/UnitedHealthcare, Cigna, Humana, and regional carriers, though availability varies by state and ZIP code.

Before you buy, compare premiums from at least three insurers. The coverage is the same across all insurers (because Medigap plans are standardized), so the only difference is price and customer service. Medicare's Plan Finder tool at Medicare.gov lets you enter your ZIP code and see which insurers sell which plans in your area and what they charge.

You can enroll in Part F during your initial enrollment window (the six-month period starting the month you turn 65 and enroll in Part B) or at any time after that. There is no annual open enrollment period for Medigap — you can buy it whenever you want, though premiums may be higher if you enroll late.

When to ask your doctor or insurance company

Ask your doctor or current insurance company what out-of-pocket costs you are paying now and whether Part F would reduce them. If you have a chronic condition that requires frequent doctor visits or specialist care, Part F may save you money despite the higher premium.

Ask your insurance company whether they use attained-age or issue-age pricing, so you understand how your premium will change over time. Ask whether they will require medical underwriting if you enroll outside your initial window.

If you are considering switching from Medicare Advantage to Original Medicare plus Part F, ask your current plan when the annual open enrollment period is and what happens to your coverage if you switch mid-year. Some Medicare Advantage plans charge a penalty if you leave before the year ends.

Frequently Asked Questions

Can I use Part F with Medicare Advantage?

No. Part F is a supplement to Original Medicare only. If you have Medicare Advantage (Part C), you cannot buy Medigap. If you want Part F, you must switch to Original Medicare during the annual open enrollment period or during a may have access to life event.

Does Part F cover prescription drugs?

No. Part F covers out-of-pocket costs for doctor visits and hospital care, but not medications. You need Part D (prescription drug coverage) for that. You buy Part D separately from a private insurance company and can enroll in it at the same time as Part F.

What if I enrolled in Medicare after January 1, 2020?

You cannot buy Part F. Federal law prohibits insurers from selling Part F to anyone who enrolled in Medicare on or after that date. You can buy Plan G (which covers almost everything Part F does except the Part B deductible) or one of the other nine Medigap plans.

Will my Part F premium go up every year?

Yes. All Medigap premiums increase annually. The amount depends on your insurer and their pricing method. Some increase because of your age, some because of inflation, and some because of claims experience. You can switch to a different insurer's plan if premiums become unaffordable, though you may face medical underwriting.

Is Part F worth the cost?

That depends on how much medical care you use. If you see doctors frequently, have specialist appointments, or expect hospital stays, Part F's comprehensive coverage may save you money despite the higher premium. If you are healthy and rarely use medical services, a less comprehensive plan with a lower premium might be better.