Medicare Supplement (Medigap) vs. Medicare Advantage
Health coverage affects so much, from how people plan for retirement to how they manage unexpected costs and stay in control as needs change with age.
That’s why Medicare decisions carry so much weight — and why many seniors explore coverage beyond Original Medicare.
At the center of that decision sit two options: Medicare Supplement (Medigap) and Medicare Advantage. Each offers a different approach to managing care, costs, and risk.
In 2023, nearly 5.3 million Medicare enrollees — roughly 39% of all Medigap users — chose Plan G, the most popular Medicare Supplement policy available. It’s built to cover nearly all of the out-of-pocket expenses Original Medicare doesn’t pay.
At the same time, Medicare Advantage continues to grow, drawing millions with bundled benefits and lower premiums.
So, what’s the real difference between these two? And how should seniors think about these options heading into 2025?
This guide breaks down Medicare Advantage vs Medicare Supplement plans, so you can choose the plan that works for your care, your budget, and your peace of mind.
Table of Content
1. What Are Medicare Supplement (Medigap) Plans?
2. What Are Medicare Advantage Plans?
3. Key Differences Between Medicare Advantage and Medicare Supplement
4. Which Plan Is Better for You?
5. How Prescription Drugs Are Handled
6. When Can You Enroll or Switch Plans?
7. FAQs About Medicare Advantage and Medigap
8. What to Keep in Mind Before You Enroll
What Are Medicare Supplement (Medigap) Plans?
Medicare Supplement insurance plans, also known as Medigap, work alongside Original Medicare (Parts A and B) to help reduce out-of-pocket costs. While Original Medicare covers many hospital and medical services, it doesn’t pay for everything. That’s where Medigap steps in.
With a Medigap plan, private insurance companies cover certain costs that Medicare leaves behind. This can include copayments for doctor visits, coinsurance for hospital stays, and deductibles for services covered under Medicare Part A or B. In some cases, Medigap also helps cover certain emergency healthcare costs while traveling outside the U.S.
Unlike Medicare Advantage, Medigap doesn’t replace Original Medicare. You still keep all your Original Medicare benefits, but Medigap helps make your costs more predictable. For many seniors, this added financial protection offers peace of mind, especially during years when unexpected medical needs arise.
To learn more about how these plans work, visit our guide on what is Medicare Supplement plans.
What Are Medicare Advantage Plans?
Medicare Advantage, also known as Part C, offers another way to receive Medicare benefits. Unlike Medigap, Medicare Advantage doesn’t supplement Original Medicare — it replaces it. When you enroll in a Medicare Advantage plan, private insurance companies approved by Medicare take over the administration of your Part A and Part B benefits.
Most Medicare Advantage plans include hospital and medical coverage, just like Original Medicare. But many plans also bundle in extra services, such as prescription drug coverage, dental, vision, hearing, fitness programs, and transportation benefits. These additional features have made Medicare Advantage plans increasingly popular heading into 2025.
Because Medicare Advantage plans are managed by private insurers, they often use provider networks like HMOs or PPOs. This means you may need to select doctors, specialists, and hospitals within the plan’s network and may require referrals for certain services.
To explore how these plans work, visit our guide on Medicare Advantage plans and how federal medicare programs work.
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Key Differences Between Medicare Advantage and Medicare Supplement
Both Medicare Advantage and Medicare Supplement plans offer ways to manage healthcare costs, but they operate in very different ways.
Comparing these plans side-by-side helps clarify which option may fit your situation.
Coverage Scope
Medicare Supplement (Medigap) works alongside Original Medicare coverage It helps pay for the costs that Parts A and B don’t fully cover, such as copayments, coinsurance, and deductibles. You still keep all your Original Medicare benefits, and Medigap fills in many of the financial gaps.
Medicare Advantage replaces Original Medicare entirely. When you enroll in a Medicare Advantage plan, your hospital, medical, and often prescription drug coverage are bundled into one plan administered by a private insurer.
Provider Networks
With Medigap, you can see any healthcare provider nationwide who accepts Medicare. There are no network restrictions, which makes it a strong option for those who want flexibility or travel frequently.
Medicare Advantage plans typically use HMO or PPO networks. These networks limit which doctors and hospitals you can visit and may require referrals for specialists. Staying within the network usually keeps costs lower, but it may restrict provider choice.
Out-of-Pocket Costs
Medigap plans usually come with higher monthly premiums. In exchange, they offer more predictable out-of-pocket costs since many deductibles, copayments, and coinsurance amounts are covered.
Medicare Advantage plans often have lower premiums, sometimes even $0, but may involve more cost-sharing as you use healthcare services. You’ll pay copays and coinsurance as you go, and these costs can vary based on your care needs each year.
Additional Benefits
Medicare Advantage plans frequently include extra benefits not covered by Original Medicare or Medigap. These may include dental, vision, hearing, fitness memberships, over-the-counter allowances, and wellness programs.
Medigap plans generally don’t offer these extras. Instead, they focus entirely on covering out-of-pocket costs tied to Medicare-approved services.
Which Plan Is Better for You?
There’s no single Medicare option that works for everyone. The choice depends on your personal healthcare needs, financial situation, and lifestyle.
Here are a few factors to help evaluate your options:
Budget:
If keeping monthly premiums low is a top priority, Medicare Advantage may be more appealing. Many Advantage plans offer lower premiums, but may lead to higher out-of-pocket costs when you use services.
Medigap typically requires higher monthly premiums but provides more predictable expenses, especially if you expect frequent care or hospital visits.
Travel Frequency:
Seniors who travel often — whether across state lines or internationally — often prefer Medigap, since it works with any provider nationwide who accepts Medicare.
Some Medigap plans also offer limited foreign travel emergency coverage. Medicare Advantage plans generally limit coverage to their provider networks, which may be restrictive for frequent travelers.
Health Conditions:
For individuals with ongoing or complex medical needs, Medigap’s predictable cost structure can make long-term care planning easier.
Medicare Advantage may work well for those who are generally healthy, use fewer services, and want access to extra benefits like dental and vision.
Preferred Doctors or Specialists:
If staying with specific doctors or specialists is important, Medigap allows access to any provider who accepts Medicare. Medicare Advantage plans require careful review of network providers to make sure your preferred doctors participate in the plan.
In many cases, Medicare Advantage may fit seniors looking for convenience, bundled benefits, and lower premiums, while Medigap may suit those who want flexibility, broader provider access, and more predictable medical costs.
See Which Medicare Plan Fits Best
How Prescription Drugs Are Handled
Prescription drug coverage is one of the biggest differences between Medicare Advantage and Medicare Supplement plans.
Medigap doesn’t include drug coverage. If you choose a Medigap plan, you’ll need to purchase a separate Medicare Part D plan to help cover prescription medications. Each Part D plan has its own formulary (list of covered drugs), premiums, copays, and pharmacy networks.
Most Medicare Advantage plans include Part D drug coverage automatically. These bundled plans simplify coverage by combining hospital, medical, and prescription drug benefits into one policy.
However, formularies still vary by plan, so check whether your medications are covered before enrolling. To stay informed about upcoming changes to drug coverage, visit our guide on Medicare Part D changes.
When Can You Enroll or Switch Plans?
Enrollment timing is another key difference between Medicare Advantage and Medicare Supplement plans. Understanding your windows for the initial enrollment period or making changes helps avoid gaps in coverage or penalties.
Medicare Supplement (Medigap) Enrollment:
For most seniors, the best time to enroll in a Medigap plan is during your Medigap Open Enrollment Period — the six months after you first enroll in Medicare Part B. During this window, you have guaranteed issue rights, meaning you can sign up for any Medigap plan without medical underwriting or denial for pre-existing conditions.
In Nevada, existing Medigap policyholders also benefit from the Medicare Birthday Rule. This rule allows you to review and switch Medigap plans each year during the 60 days following your birthday, with guaranteed acceptance into any plan of equal or lesser coverage.
You don’t have to go through medical underwriting during this period, making it easier to find a better rate or plan fit.
Medicare Advantage Enrollment:
For Medicare Advantage, the Annual Enrollment Period (AEP) runs from October 15 to December 7 each year. During AEP, you can enroll in, switch, or drop a Medicare Advantage plan.
There’s also the Medicare Advantage Open Enrollment Period (MA OEP) from January 1 to March 31. This allows seniors already enrolled in a Medicare Advantage plan to switch to a different Advantage plan or return to Original Medicare if needed.
FAQs About Medicare Advantage and Medigap
Here are answers to some common questions important to anyone comparing coverage types:
Is Medigap going away in 2025?
No. Medigap policies remain available, and updates for 2025 include standardized plan designs and expanded digital enrollment options. Your ability to choose supplemental coverage continues unchanged.
Can you switch from Medicare Advantage to Medigap?
Yes, but timing matters. If you’re transitioning during the Annual Enrollment Period (Oct 15–Dec 7), you can return to Original Medicare.
After that, your best chance to add a Medigap plan without medical underwriting is during your Medigap Open Enrollment Period — typically the six months after enrolling in Part B. Nevada’s Birthday Rule also allows guaranteed Medigap switches within 60 days of your birthday each year.
Can I have both Medigap and Medicare Advantage?
No. Medigap is designed to work with Original Medicare (Parts A & B). If you’re enrolled in a Medicare Advantage plan, you’re actively replacing Original Medicare and can’t hold a Medigap plan at the same time.
How do Parts A and B fit into all this?
All Medicare options begin with Parts A (hospital care) and B (medical care). Medigap helps cover what they don’t. Medicare Advantage replaces these parts with a bundled private insurance plan that usually includes prescription drug coverage.
For a deeper look, check out our guide on Medicare Part A.
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What to Keep in Mind Before You Enroll
Choosing between Medicare Advantage and Medigap isn’t a matter of which plan is better overall. It’s a question of which plan works better for you.
These decisions can shape how care fits into your daily life, how flexible your provider choices are, and how predictable your healthcare spending will be, both now and years from now. What feels like a small tradeoff today can have a larger impact down the road, depending on your health, your financial comfort, and how your needs evolve.
The most important move is to approach Medicare planning actively. Plans change. Benefits adjust. Premiums shift. Staying engaged in the process gives you more control over your care and your costs.
If you’re weighing your options, a licensed Medicare advisor will help break down the details, answer your questions, and help you feel confident in the plan you select.
When you’re ready, Senior Insurance Agency is here to help. Contact us today!
About the Author: Aliana Rushing
I have worked at Senior Insurance Agency since 2016, and became a licensed insurance agent in 2018. I specialize in senior products (Medicare Supplement, Medicare Advantage Part C, and Part D). I take much pride in my work and in providing my clients with exceptional service. My approach to Medicare…