Medicare Supplement Cost Calculator
Add up the true annual cost of Original Medicare with a Medigap supplement and a Part D drug plan.
How it works
Annual cost = (Part B + Medigap + Part D) × 12 + expected out-of-pocket
Original Medicare pairs Part A (hospital, usually premium-free) and Part B (medical, a monthly premium) with two optional add-ons: a Medigap supplement that pays most of the deductibles and coinsurance Medicare leaves behind, and a Part D plan for prescriptions. The trade-off versus a Medicare Advantage plan is higher predictable premiums in exchange for very low out-of-pocket costs and freedom to see any Medicare-accepting provider. Medigap premiums vary widely by plan letter, age, gender and state.
Worked example
A retiree paying $185 for Part B, $150 for a Plan G Medigap and $40 for Part D spends $375 a month, or $4,500 a year in premiums. Adding $300 of expected out-of-pocket brings the total to about $4,800 for the year.
Sources: Medicare.gov — Medigap
Frequently asked questions
What is Medigap?
Medigap, or Medicare Supplement Insurance, is a private policy that fills the "gaps" in Original Medicare — the Part A and B deductibles, copays and coinsurance. Plans are standardized by letter (A through N), so a Plan G is the same benefits from any insurer, differing only in price.
Is Medigap better than Medicare Advantage?
Medigap plus Part D means higher monthly premiums but very predictable, low out-of-pocket costs and any-provider access. Medicare Advantage has lower or no premiums but network restrictions and variable out-of-pocket costs. The right choice depends on your health, budget and providers.
Does this include Part A?
Part A (hospital insurance) is premium-free for most people who paid Medicare taxes for 40 quarters, so it is not added here. If you must buy Part A, add its premium to the monthly total.
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Educational estimate, not insurance or financial advice — real premiums and coverage depend on underwriting, your state and the specific policy.