Medicare Supplement (Medigap) Plans Explained
A Medicare Supplement works alongside Original Medicare to help cover the out-of-pocket costs it leaves behind, usually with broader doctor access. A licensed advisor compares options for you, free of charge.
Free. No obligation. No flood of calls.
Want to keep your doctors? Here's how a Supplement works.
If keeping a wide choice of doctors matters to you, a Medicare Supplement is worth a close look. It pairs with Original Medicare and helps with the costs Medicare alone doesn't cover. Health Trust Financial is the only company the Ramsey Team recommends to help you find health insurance, and an advisor will help you compare without the jargon.
A Medicare Supplement, also known as Medigap, is private health insurance designed to fill the "gaps" in Original Medicare (Part A and Part B). When you have a Supplement, the federal government pays its share of your Medicare-approved healthcare costs first, and then your Medigap policy steps in to pay its share.
This approach provides the highest level of freedom and predictability in retirement healthcare. You do not have to worry about restrictive networks or unexpected medical bills draining your savings. However, it requires a higher upfront monthly premium compared to Medicare Advantage.
What to know
Works alongside Original Medicare.
It pairs with it rather than replacing it.
Helps with out-of-pocket costs.
Things like coinsurance and deductibles.
Broader doctor access.
It usually offers wider access to doctors who accept Medicare.
What Original Medicare leaves behind
Many people assume that once they turn 65, Medicare covers everything for free. It does not. Original Medicare leaves behind significant gaps, which is exactly why Supplements exist.
Under Part B (medical insurance), Medicare typically pays 80% of approved costs. You are responsible for the remaining 20% coinsurance. Crucially, Original Medicare has no out-of-pocket maximum. If you need a $100,000 surgery, your 20% share is $20,000. If you need ongoing expensive treatments, there is no cap on what you might owe.
That lack of a safety net is the whole argument for a Medicare Supplement. A Medigap policy steps in to pay that 20% coinsurance, as well as hospital deductibles and copays, effectively capping your catastrophic medical risk.
Medigap plans are standardized. That is the key fact.
In most states, Medicare Supplement policies are standardized and identified by letters (Plan A through Plan N). The federal government dictates exactly what each letter plan must cover.
This means a Plan G from Carrier X offers the exact same medical benefits as a Plan G from Carrier Y. There is no difference in coverage, no difference in the doctors you can see, and no difference in how claims are paid.
What differs is the price and the company's financial stability. This means shopping for a Medigap plan is genuinely just shopping on price and carrier reputation. This is unusually good news for the consumer. An advisor can pull quotes from top carriers in your zip code and simply show you the most cost-effective option for the exact same coverage.
| Feature | Medicare Supplement (Medigap) | Medicare Advantage |
|---|---|---|
| How it works | Works alongside Original Medicare | Replaces Original Medicare with a private bundled plan |
| Doctor access | Usually broader, any doctor who accepts Medicare | Within a network (HMO/PPO) |
| Extra benefits | Generally not included | Often includes dental, vision, and more |
| Prescription drugs | Usually needs a separate Part D plan | Often built in |
| Monthly premium | Often higher | Often lower |
| Cost when you need care | More predictable, more covered up front | Copays and coinsurance as you go |
| Changes year to year | More stable | Benefits and networks can change annually |
| Switching later | Can switch to Advantage easily during AEP | Switching to Medigap later may require medical underwriting |
This is a general comparison. Your advisor will walk you through the specifics for your situation.
The Medigap Open Enrollment Period, and why it matters more than anything else on this page
There is a one-time window when you have guaranteed-issue rights for a Medicare Supplement. During this specific timeframe, an insurance company is legally required to sell you any Medigap policy it offers, at the best available rate, regardless of your health history. They cannot deny you or charge you more because of a pre-existing condition.
Outside of that window, those guarantees disappear. If you apply for a Medigap policy later, the insurance company can use medical underwriting. They will look at your health records, and if you have developed a condition like heart disease or diabetes, they can deny your application entirely.
Missing this guaranteed-issue window is one of the most expensive mistakes available in Medicare, and it is irreversible. The exact timing depends on when you turn 65 and enroll in Part B. Do not guess on the dates. Let an advisor model your specific timeline so you don't accidentally close the door on your options.
You still need Part D
A Medicare Supplement policy covers medical and hospital costs, but it does not cover prescription drugs. If you choose a Supplement, you must also purchase a standalone Medicare Part D plan to cover your medications. Skipping Part D can result in a permanent late enrollment penalty.
Common mistakes
- Missing the guaranteed-issue window: Failing to enroll during your Medigap Open Enrollment Period and losing the right to buy a policy without medical underwriting.
- Assuming all carriers' Plan G is different: Believing a higher premium means better medical coverage. The benefits are standardized by law; you should shop primarily on price and carrier stability.
- Forgetting Part D: Assuming the Supplement covers prescriptions, failing to buy a Part D plan, and getting hit with a lifelong late enrollment penalty.
- Choosing Advantage at 65 and finding the door closed later: Taking the $0 premium at 65, getting sick at 70, and discovering you can't pass underwriting to switch to a Supplement.
What to ask before you decide
- "Exactly when does my guaranteed-issue Medigap Open Enrollment Period start and end?"
- "What is the current monthly premium for a Plan G from the top three carriers in my area?"
- "How historically stable have this specific carrier's rate increases been over the past five years?"
- "Does this Supplement include any foreign travel emergency coverage?"
- "What standalone Part D plan pairs best with this Supplement based on my specific medications?"
- "Are there any household discounts available if my spouse also enrolls?"
- "If I delay Part B because I'm still working, how does that affect my guaranteed-issue rights?"
- "What is the difference in out-of-pocket exposure between Plan G and Plan N for someone with my health profile?"
"He was very knowledgeable and helped me with my insurance questions. He gave me several options and didn't push me to make a decision for coverage. He considered my financial situation and my current coverage. I would highly recommend him to my friends."