Medicare guidance
Medicare Supplement Plans F and C: Eligibility and Premium Considerations
Understand who can still buy Medigap Plans F and C, how Plan F compares with Plan G and what existing members should review before switching.
Eligibility first
The Rule Concerns When You Became Eligible for Medicare
Plans C and F include coverage of the Part B deductible. They are not available to people newly eligible for Medicare on or after January 1, 2020. People eligible before that date may still be able to buy them, including some people who delayed enrollment. Eligibility for Medicare and the date you actually enrolled are different questions.
A person under 65 who qualified for Medicare before 2020 may have a different history from someone first qualifying at 65 later. Confirm the eligibility record, state availability and insurer requirements. Being in the permitted eligibility group does not automatically establish a right to buy any policy without underwriting.
Existing coverage
Do You Have to Give Up Plan F or C?
The eligibility restriction does not require existing members to drop their policies. Review whether your current coverage, premium and insurer service still fit. A letter mentioning the 2020 rule should not be mistaken for an instruction to cancel a valid policy.
If someone urges you to replace coverage immediately because Plan F is “going away,” ask what specific policy or carrier notice they mean. The rule limiting new eligibility is different from your own insurer’s obligations under your policy.
Benefit differences
How Do Plans F, C and G Compare?
| Benefit | Plan F | Plan C | Plan G |
|---|---|---|---|
| Part B deductible | Covered | Covered | Not covered |
| Part B excess charges | Covered | Not covered | Covered |
| Who may be eligible to buy? | Requires Medicare eligibility before January 1, 2020, plus applicable purchase rules. | Requires Medicare eligibility before January 1, 2020, plus applicable purchase rules. | Available to newer Medicare beneficiaries, subject to purchase rules. |
This is a focused comparison, not the entire benefit chart. Medicare’s official comparison lists the remaining standardized benefits. Medicare Supplement Plan C is not Medicare Part C; Part C means Medicare Advantage.
Premium review
Compare Plan F’s Extra Premium with What It Covers
For standard Plan F versus standard Plan G, the Part B deductible is the key standardized benefit difference. Compare the full annual premium difference with the current annual Part B deductible, then consider eligibility, discounts and any transition costs. Use current quotes rather than a national average.
That calculation can identify a question worth pursuing. It cannot guarantee approval, future savings or that replacing an existing policy is the right decision. The Medigap premium-increase guide provides a practical order for that review.
Closed blocks
Ask About the Actual Policy Pool
People sometimes use “closed block” to describe a policy form no longer sold to new applicants. That is not automatically the same as the federal restriction on who can buy F or C. Ask the insurer whether your exact form remains open to eligible applicants and how its rates are developed.
A shrinking or aging group can be a concern to investigate, but “all Plan F premiums will rise by a particular percentage” is not a reliable conclusion. Claim experience, expenses, rating method and state oversight affect the insurer’s actual rate decisions. Do not substitute a prediction for a current comparison.
Your next step
Keep the Replacement Process Separate from the Decision
Bring your policy letter, premium, original effective date and Medicare eligibility history to the review. Missouri members should check the Anniversary Rule for qualifying same-plan changes; that protection is not a blanket right to move from F to G without underwriting.
Confirm any replacement’s acceptance and start date before canceling. If keeping Plan F or C is still the most suitable available option, understanding the costs is useful even when no switch follows.
Official information
Sources and Further Reading
- Medicare: Compare Medigap benefits and pre-2020 eligibility
- Medicare: Medigap costs
- Medicare: Changing policies
- Medicare: Buying Medigap
Sources checked September 11, 2026.
Independent Medicare guidance
Make Your Next Medicare Decision with Confidence
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Thompson Medicare Brokerage is not connected with or endorsed by the U.S. government or the federal Medicare program. Educational information does not replace an official coverage or eligibility determination. Your circumstances and current Medicare and plan rules control.