Medicare Supplement

Medicare Supplement Plans -- How they workMedicare Supplement plans (also known as Medigap plans) are insurance policies sold by private companies that help pay the “gaps” in Original Medicare (Parts A and B). These gaps include deductibles, copays, and coinsurance, which can otherwise add up quickly — especially for surgeries, serious illness, or hospital stays. You must be enrolled in Original Medicare -- Parts A and B.

What Do Medigap Plans Cover?                                                          Medicare supplement plans extend the coverage limits of Original Medicare (Parts A and B), which typically pay 80% of the treatment costs covered by Medicare. Medicare supplement plans then pay the remaining 20% after Original Medicare paid the first 80%.

Medicare supplement plans help pay for:

-- Hospital costs -- deductibles and coinsurance (Part A)

-- Medical coinsurance for office visits and surgeries (Part B)

-- Skilled nursing facility care

-- Blood transfusions -- the first 3 pints

-- Foreign travel emergency care (in some plans)

Example Coverage for a $150,000 Knee Replacement Surgery

Patient: John

Coverage: Original Medicare (Parts A & B) + Medigap Plan G

Status: Has already met his Part B deductible for the year

Total Billed Charges: $150,000

This is the hospital’s full, non-negotiated amount for:

-- Hospital stay

-- Surgeon’s fee and consultations

-- Diagnostics and imaging

-- Anesthesia

-- Implant

-- Post-op care

Who Pays What?

Medicare Pays 80% of the costs

Plan G Pays the Remaining 20%:

John Pays $0

What’s Not Included? Medigap does not cover:

-- Prescription drugs (you’ll need a separate Part D plan)

-- Routine dental, vision, or hearing

-- Long-term care (and neither do Advantage plans)

Standardized Plans

Unlike Medicare Advantage plans, Medigap plans are completely standardized in most states. This means that any plan from one carrier offers the exact same coverage as the same plan from any other carrier — only the monthly premium differs. That's right! The only difference between carriers is the varying premium each one charges for the exact same coverage plan. The most popular plan today is Plan G, which covers nearly all out-of-pocket costs except the Part B deductible ($257 for 2025).

Costs For Medicare Supplement:

-- Monthly premium to the Medigap company for supplemental coverage

-- Annual deductible with supplemental coverage: $257 for 2025

-- your Part B premium to Medicare. $185 per month for most people. The same Part B cost applies to Advantage plans.

-- Part A premium is $0 cost for most people.

Freedom to Choose Providers

With Medigap, you can see any doctor or specialist who accepts Medicare — no networks, no referrals. Coverage is nationwide and includes emergency coverage for foreign travel.

Enrollment Tip

You have a 6-month Medigap open enrollment period when you first enroll in Part B (usually at age 65). During this time, you can’t be denied coverage and you won’t pay more due to pre-existing health conditions.