Understanding Medicare Supplement Plans: A Guide for New Medicare Enrollees
Medicare Supplement (Medigap) plans fill the gaps in Original Medicare. Here is how they work, what the different plan letters mean, and how to choose the right one.
Understanding Medicare Supplement Plans: A Guide for New Medicare Enrollees
Original Medicare covers a lot -- but it leaves significant gaps. The 20% coinsurance under Part B has no annual cap. The Part A hospital deductible applies every benefit period. Without supplemental coverage, a serious illness can cost tens of thousands of dollars out of pocket.
Medicare Supplement plans -- also called Medigap -- are private insurance policies that fill these gaps.
How Medigap Works
Medigap plans work alongside Original Medicare. When you receive care:
- Medicare pays its share (typically 80% of approved costs after deductibles)
- Your Medigap plan pays its share (the remaining 20%, deductibles, or other cost-sharing depending on your plan)
- You pay little or nothing
Medigap plans are standardized by the federal government. Every Plan G from every carrier offers identical coverage -- the only difference is the premium and the company's financial stability and customer service.
The Medigap Plan Letters
There are 10 standardized Medigap plan types: A, B, C, D, F, G, K, L, M, and N. The most popular are:
Plan F: The most comprehensive plan -- covers everything including the Part B deductible. Available only to those who became eligible for Medicare before January 1, 2020.
Plan G: Covers everything Plan F covers except the Part B deductible ($166 in 2016). The best option for new Medicare enrollees. After paying the deductible once per year, you pay nothing for Medicare-covered services.
Plan N: Covers everything Plan G covers except Part B excess charges and small copays ($20 for office visits, $50 for ER visits). Lower premium than Plan G.
Plan K and L: High-deductible options with lower premiums. You pay a percentage of costs until you reach the plan's out-of-pocket limit.
What Medigap Does NOT Cover
Medigap plans do not cover prescription drugs (you need a separate Part D plan), dental, vision, hearing, or long-term care.
When to Enroll: The Guaranteed Issue Window
The most important thing to know about Medigap: you have a 6-month guaranteed issue window starting when you're both age 65 AND enrolled in Part B. During this window, no insurer can deny you coverage or charge more based on your health history.
After this window closes, insurers can ask health questions and deny coverage based on pre-existing conditions. If you develop a serious health condition, you may be unable to get Medigap at any price.
Enroll during your guaranteed issue window. Don't wait.
How Much Does Medigap Cost?
Premiums vary by plan type, carrier, age, gender, tobacco use, and location. In Florida, Plan G premiums for a 65-year-old non-smoking woman typically range from $100-$160/month.
Medigap vs. Medicare Advantage
Medigap works with Original Medicare and gives you access to any Medicare-accepting provider nationwide. Medicare Advantage replaces Original Medicare with a private plan that has networks, copays, and usually a $0 premium.
For seniors who value freedom of choice and predictable costs, Medigap is often the better long-term choice -- especially if you have established specialist relationships or travel frequently.
We do not offer every plan available in your area. Please contact Medicare.gov or 1-800-MEDICARE to get information on all of your options.
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About the Author
William Gray
Independent Medicare BrokerUS Air Force Veteran · Florida Medicare Specialist
William Gray is an independent Medicare insurance broker based in Daytona Beach and Palm Coast, FL. A US Air Force veteran (A-10 crew chief, Germany), he spent years in corporate insurance before going independent to serve Florida seniors directly. He has helped more than 1,000 clients across Northeast Florida compare Medicare Advantage, Medigap, and Part D plans — always at no cost to the client.