What is “Medigap” insurance?
What Is Medicare Supplemental Insurance?
A Clear, Easy Guide to Understanding Medigap Coverage
When people enroll in Original Medicare (Part A and Part B), they’re often surprised to learn that Medicare doesn’t cover everything. There are deductibles, copays, and coinsurance costs that can add up quickly—especially for those who visit doctors frequently or manage chronic health conditions.
That’s where Medicare Supplemental Insurance, also known as Medigap, comes in.
Let’s break down what it is, how it works, and why so many people choose it.
What Is Medicare Supplemental Insurance (Medigap)?
Medicare Supplemental Insurance, or Medigap, is private health insurance designed to help cover the “gaps” in Original Medicare.
These gaps include:
Medicare deductibles
Coinsurance
Copayments
Medigap acts as a financial safety net, helping you manage out-of-pocket expenses that would otherwise come directly from your own budget.
How Medigap Works
When you have both Original Medicare and a Medigap policy:
Medicare pays its share of approved healthcare costs.
Your Medigap plan pays its share of the remaining costs.
This teamwork helps reduce or eliminate out-of-pocket expenses, depending on the plan you choose.
You’ll pay a monthly premium for Medigap, but in return you get predictable and stable healthcare costs throughout the year.
What Medigap Covers
While coverage varies by the plan you choose (labeled Plan A, B, C, D, F, G, K, L, M, and N), most Medigap plans help pay for:
Medicare Part A coinsurance & hospital costs
Medicare Part B coinsurance or copayments
Blood (first 3 pints)
Part A hospice care coinsurance
Skilled nursing facility care coinsurance
Part A deductible
Foreign travel emergency care (in some plans)
Some plans—like Plan G and Plan N—are especially popular for their strong overall coverage.
What Medigap Does Not Cover
Medigap doesn’t cover everything. It does not include:
Prescription drug coverage (you need a separate Part D plan for that)
Dental, vision, or hearing benefits
Long-term care
Fitness memberships or extra perks commonly found in Medicare Advantage plans
Medigap is strictly designed to help with Medicare-related out-of-pocket costs.
Who Is Eligible for Medigap?
To buy a Medigap policy, you must:
Be enrolled in Medicare Part A and Part B
Live in a state where the plan is offered
Your best time to enroll is during your Medigap Open Enrollment Period—a 6-month window that starts the month you turn 65 and are enrolled in Part B.
During this time, you cannot be denied coverage or charged more due to pre-existing conditions.
Why People Choose Medigap
Medigap offers several key advantages:
1. Predictable Costs
Your medical expenses become more manageable and consistent throughout the year.
2. Nationwide Coverage
You can visit any doctor or hospital in the U.S. that accepts Medicare—no networks, no referrals.
3. Peace of Mind
You’re protected from large, unexpected medical bills.
4. Flexibility
You can pair Medigap with any standalone Part D prescription drug plan.
Medigap vs. Medicare Advantage: What’s the Difference?
Many people confuse Medigap with Medicare Advantage—but they’re very different.
MedigapMedicare AdvantageSupplements Original MedicareReplaces Original MedicareNo networks — see any doctor that accepts MedicareUses provider networks (HMO/PPO)Predictable out-of-pocket costsCosts vary by plan and usageNo extra benefits like dental/visionOften includes dental, vision, hearing, etc.Works nationwideCoverage is typically local
The right choice depends on your lifestyle, budget, and healthcare needs.
Final Thoughts
Medicare Supplemental Insurance (Medigap) is a powerful tool for anyone who wants predictable medical costs, the freedom to see any Medicare-accepting provider, and added financial protection. While it doesn’t replace Original Medicare or provide extra perks, it fills important gaps that help many beneficiaries feel secure and prepared.