Medicare Supplement Plan C: Coverage, Costs, Pros & Cons

Medicare Supplement Plan C is a Medigap policy sold by private insurers to fill the cost gaps in Original Medicare. It pays both the Part A and Part B deductibles, skilled nursing facility co-insurance and all Part B cost-sharing. Federal law standardizes these benefits, so Plan C coverage is identical regardless of which insurer sells it. 

But Plan C is no longer available to new enrollees. Congress phased it out for anyone who became Medicare-eligible on or after Jan. 1, 2020, under the Medicare Access and CHIP Reauthorization Act of 2015. Beneficiaries already enrolled before that date keep their Plan C coverage and can't be dropped by their insurer.

Plan C covers eight standard Medigap benefits, including both Medicare deductibles, hospice care co-insurance and skilled nursing facility costs. Plans A and B don't cover skilled nursing or hospice co-insurance. Plans G and N cover most Plan C benefits but skip the Part B deductible entirely. Plan C picks up what Medicare leaves uncovered at the points of highest cost exposure, with no provider network restrictions.

Medicare Supplement Plan C leaves six categories uncovered. Part B excess charges are the biggest gap for high-frequency Medicare users, billed when a provider charges above Medicare's approved rate and doesn't accept Medicare assignment. No Medigap plan sold to new enrollees covers the remaining five gaps either, so these exclusions apply across the board. 

• Part B excess charges (covered by Plan F and Plan G)
• Prescription drugs (requires a separate Medicare Part D plan)
• Long-term care, including non-skilled nursing home care
• Dental care (not covered by any Medigap plan)
• Vision care
• Private-duty nursing

With no network restrictions and near-zero out-of-pocket costs beyond the monthly premium, Plan C offers broad financial protection unavailable in any plan sold today. And it's the only Medigap plan that covers the Part B deductible, a benefit worth $283 in 2026. The trade-off is cost: premiums often run higher than Plan G for one line item of additional coverage.

Plan C premiums depend on age, state, tobacco use and pricing method. Per MoneyGeek's analysis of Medicare Supplement plan costs, a 65-year-old on attained age pricing pays $248 per month on average. Community-rated pricing averages $387 per month for the same enrollee. By 75, attained age premiums rise to $347 per month.

Plan C and Plan F are the only two Medigap policies that ever covered both Medicare deductibles. Plan F also covers Part B excess charges (the difference between a provider's bill and Medicare's approved rate). Plan C covers everything Plan F covers except those charges. Neither plan is available to new enrollees who became Medicare-eligible after Jan. 1, 2020, which makes them the only two Medigap policies closed to new enrollees since January 2020.

Policyholders who became Medicare-eligible before 2020 hold a benefit no new plan offers: full coverage of the $283 Part B deductible. That savings disappears permanently when you drop Plan C. Before switching, run the numbers. If your Plan C premium runs less than $283 per year above an equivalent Plan G policy, Plan C costs less overall, even though Plan G's monthly rate often looks lower at a glance. 

• Plan C covers the $283 Part B deductible in full each year, while Plan G policyholders pay that amount out of pocket.
• Plan C is guaranteed renewable, meaning an insurer can't cancel it as long as premiums are paid.
• Switching plans outside Medigap open enrollment requires medical underwriting, and coverage can be denied based on health history.
• At 65, attained age Plan C premiums average $248 per month, rising to $347 by age 75, a cost trajectory to weigh alongside the $283 annual deductible savings.

New Medicare enrollees can't buy Plan C, but several plans offer comparable or partial coverage. The best Medicare Supplement plans today center on Plan G, which covers every Plan C benefit except the Part B deductible.

Medicare Supplement Plan C is worth keeping for anyone eligible to hold it. Its coverage of the $283 Part B deductible is a benefit no new Medigap plan offers, and giving it up means paying that amount out of pocket each year. Compare the annual premium difference against the deductible before switching to Plan G. The math often favors Plan C.

We've answered the most frequently asked questions about Medicare Supplement Plan C: