Skip to main content

This guide will help you understand what Medicare Advantage does and what a Medicare supplement plan can help with.

Sept. 15, 2025

When you join Medicare, there are a lot of different choices. It’s important to know what each one does so you can make a good choice that fits your needs. One common confusion is between Medicare Advantage vs. Medicare Supplement Insurance.

This guide will help you understand what Medicare Advantage does and what a Medicare supplement plan can help with.

What is Medicare Advantage?

Medicare Advantage is also known as Medicare Part C. It’s a full replacement plan for Original Medicare, offering the same coverage along with added benefits.

These plans include Medicare Part A (hospital coverage), Medicare Part B (medical visits), and often Medicare Part D (prescription drug coverage).1 They offer the same preventive benefits as Original Medicare, including annual wellness exams.

Medicare Advantage plans are sold by private insurance companies instead of being provided through the government.

Medicare Advantage vs. Original Medicare

Medicare Advantage and Original Medicare have some similarities, but there are also important differences.

Some of the main differences when you use Medicare Advantage are:

  • Medicare Advantage plans generally require you to use their specific provider network for medical care and prescription drugs1
  • Medicare Advantage plans will also have different out-of-pocket costs, including deductibles and co-payments1
  • Some Medicare Advantage plans require you to pay a premium that’s higher than your normal Part B premium1
  • You are likely to need pre-approval from your plan before you get specific medical care or prescription drugs1
  • Medicare Advantage plans may offer added benefits, including vision, dental and discounts on healthy living services1

You’ll get the full details for your Medicare Advantage plan each year when you get the Annual Notice of Change and Evidence of Coverage.

The Notice of Change is sent by September 30 each year. It outlines any changes in coverage, cost, provider network and other provisions for the next year.1 The Evidence of Coverage is sent by October 15 of each year and gives information about what the plan covers, how much you pay out-of-pocket and other details.1

Every Medicare Advantage plan is different, so be sure to compare your options and fully understand the costs and benefits before you become a member.

Who qualifies for Medicare Advantage?

Anyone who has Medicare Part A and Medicare Part B, who is lawfully in the U.S. and lives in the plan’s service area, can join a Medicare Advantage plan. Medicare Advantage plans will cover you even if you have a pre-existing condition.

If you have medical insurance through an employer, you may not be able to get a Medicare Advantage plan without losing your employer coverage.1 You’ll want to talk to your employer’s benefits specialist to see if you can have Medicare Advantage along with the work-related coverage.

Some employers offer a Medicare Advantage plan as a retiree health plan. You can only be in one Medicare Advantage plan at a time, so if you have a Medicare Advantage plan as a retiree, you cannot also join one personally.1

How to enroll in Medicare Advantage

If you want to enroll in Medicare Advantage, you can choose that choice during your first enrollment period around your 65th birthday. You can also choose a Medicare Advantage plan during Annual enrollment, which is between October 15 and December 7 of each year.1

If you already have a Medicare Advantage plan, you can choose a different one or return to Original Medicare during the Medicare Advantage Enrollment Period. This period is between January 31 and March 31 each year.1

Sometimes, a life change will give you a special enrollment period that you can use to change Medicare plans.1 During these special enrollment periods, you can choose a Medicare Advantage plan if you’d like.

To compare Medicare Advantage plans and choose one that fits your needs, you can search online through Medicare.gov. You can also call 1-800-MEDICARE or work with an insurance agent.

What is Medicare Supplement Insurance?

Medicare Supplement Insurance is also known as Medigap. This coverage helps you pay for some of the out-of-pocket costs you have when you use Original Medicare.1

Medicare Supplement Insurance doesn’t offer any coverage directly — it simply helps pay the premiums, coinsurance and deductibles for your Original Medicare coverage, depending on the plan.

You can’t have a Medigap policy if you have Medicare Advantage. In fact, it’s illegal for someone to try to sell you Medicare Supplement Insurance if you have Medicare Advantage unless you’re in the process of switching back to Original Medicare.1

Understanding Medigap plans

Medigap plans are labeled with letters, and every plan with the same letter has to offer the same payment benefits, no matter which company sells the plan. So every Medigap Plan N will be the same. The only thing to compare is the monthly premium for each Medigap plan.2

The plans are labeled A, B, C, D, F, G, K, L, M and N. Some plans are not available to those who turned age 65 on or after January 1, 2020.3 You can use the Medicare.gov website to compare the benefits of each plan.

Depending on the plan, these benefits may include:3

  • Covering your Part A coinsurance and hospital costs up to an additional 365 days after your Medicare benefits are used
  • Part B coinsurance or copayment
  • The first three pints of blood you need for medical treatment
  • Part A hospice care coinsurance or copayment
  • Skilled nursing facility care coinsurance
  • Part A and/or Part B deductible
  • Part B excess charges
  • Emergency medical care when you travel outside the U.S.
  • 100% coverage after you hit the out-of-pocket limit listed in the plan

Some insurance companies have a few extra services added to their plans, such as telehealth choices or discounts on services that promote healthy living.

Medigap doesn’t cover long-term care, dental, vision, hearing aids or glasses, or private-duty nursing.2

Medicare Advantage vs. Medicare Supplement Insurance

Since Medicare Supplement Insurance can only be used if you have Original Medicare, it’s not related to Medicare Advantage.

A Medicare Advantage plan is another way to get Medicare coverage if you don’t want Original Medicare. A Medigap plan only helps pay for some of the costs Original Medicare doesn’t cover, like deductibles and coinsurance.2

You can either have a Medicare Advantage plan or Original Medicare with added choices like Part D for prescription coverage and Medigap to help with out-of-pocket costs.

Who qualifies for Medigap?

You can buy Medicare Supplement Insurance (Medigap) if you have Original Medicare Part A and Part B.

One thing that makes Medigap different from other health coverage is that providers can deny coverage or charge significantly more for pre-existing conditions unless you join during the first enrollment period when you first get Part B.2

You have a one-time Medigap open enrollment period that starts the first month you get Part B and lasts for six months. During this time, you have guaranteed issue rights, which means you can choose any Medigap policy, and a company cannot deny your coverage for having a pre-existing condition.2

This open enrollment period only happens once — it does not repeat every year.2 If you’re interested in Medicare Supplement Insurance, this is the best and easiest time to join.

You can sign up for Medigap plans at any time after your first enrollment period, but you may have limits on what plans you can choose.2 You will also be subject to medical screenings that can result in a higher premium or the company refusing to issue a Medigap policy.

If you have a retiree health policy, you may get similar benefits to Medigap through that plan. Medicare pays first, and then your retiree plan provides benefits that can help with deductibles, coinsurance and more.

How to get Medigap

To get Medigap, you can compare choices online and sign up for the plan you’re interested in. Be sure you understand the pricing. Since all the plans are standardized, the monthly premium is the only difference.2

Some pricing is not based on your age, while other plans do base the price on how old you are. Some plans may also raise the premium as you get older.2

Plans can also offer discounts for non-smokers, married people, paying yearly, and other factors. Depending on your state, you may have a Medicare SELECT program that limits you to specific providers if you want help with costs, but the premium is lower. You’ll want to take all of this into account before you choose a plan.

To get help comparing Medigap plans and enrolling, you can get in touch with your State Health Insurance Assistance Program (SHIP) using the number found at shiphelp.org.

WellMed is your source for older adult health care

If you’ve ever felt like your health worries aren’t taken seriously because of your age, you’ll love the care you get at WellMed. Located in Texas and Florida, we tailor our services to the needs of older adults and have a highly qualified team of age-friendly doctors and specialists.

We’re proud to accept Medicare and many Medicare Advantage plans. If you’re ready for health care attuned to your needs, call a WellMed clinic for an appointment.

Disclaimer

For full information, visit www.medicare.gov or call 1-800-MEDICARE (TTY users should call 1-877-486-2048), 24 hours a day/7 days a week.

Sources:

Find a doctor

At WellMed, we provide personalized primary care for people with Medicare. Our doctors listen with care and compassion, building strong relationships that empower you at every step. Our goal is simple, to provide the best care so you can live your best life.