Is just Medicare Part A and Part B enough coverage, or do I need supplemental insurance?

Question

Casey Ahlbum · Accepted Answer

I don't recommend that anyone just have part A and B alone. There are some significant gaps in coverage, and no maximum out of pocket cost. 

Adding a supplemental plan can be the best approach to cover those gaps, for most seniors, as the premiums are predictable and your retirement savings is protected against significant out of pocket costs. Seniors with Medicare plus a Medicare Supplement can see any Medicare doctor in the country, or go to any hospital, without worrying about networks or approvals. 

Medicare Advantage can also help limit out of pocket costs and will cost less in the short term. However, advantage plans are known as "managed care" meaning that you have to stay within a network, they can require referrals and pre-approvals, plus you'll pay cost sharing (co-pays, co-insurance) up to a maximum out of pocket limit that must be reached before you're covered in full. Out of pocket limits will typically average $5000 to $7000 in network and much higher if any of your providers was an out of network provider. 

For most seniors, the predictable costs, freedom of choice, and limited out of pocket exposure makes a Medicare Supplement plan the best long term choice.

Annelies Van Schie · Answer

Unfortunately, to avoid a late enrollment penalty fee for life in the future; No. The minimum you need to add to Part A & B is a Part D - Drug plan. If you do not take any prescription drugs, select the plan with the lowest monthly premium. If you do take prescription drugs, check on www.medicare.gov website with your drug list and a variety of pharmacy options what the plan is with the lowest total cost. A Medigap plan is options. 

OR you can you get a Medicare Advantage plan with drug prescription coverage. Then you can also avoid a late enrollment penalty fee.

The reasons why people do select a Part C - Medicare Advantage plans  or a Medigap plan wth their Part D - Drug plan, is because Medicare Part A & B does not have a maximum out of pocket cost that limits you cost annually. Hope this clarifies this matter.

John Becker · Answer

Original Medicare (Part A and Part B) is generally not enough coverage for most, as it typically leaves you with 20% coinsurance, high deductibles, and no maximum out-of-pocket limit. Supplemental insurance—such as Medigap or a Medicare Advantage plan—is usually required to cover these gaps and protect against high, unpredictable medical costs.

Answered by John Becker on May 4, 2026

Agent Licensed in WI & MN

Answered by John Becker Medicare Insurance Agent

Michael Andrews · Answer

The question is, is just Medicare Part A and Part B enough coverage, or do I need supplemental insurance? The short answer is it really depends on your situation. However, you are exposed to a large exposure of that 20% with no maximum out of pocket, as well as no prescription drug coverage if you just had Medicare A and B.

Most people don't either get a Medicare supplement with a prescription drug plan, or they'll get a Medicare Advantage plan, for a couple of reasons. Number one, you limit your capped out-of-pocket exposure. Number two, you basically cannot get access to additional benefits that can help you through your health journey. And number three, you just want to make sure that whatever you decide to choose will be the best fit for you, and a plan that you find the most value with.

Melanie Rogers · Answer

It is not enough coverage as A and B only covers 80% and the 20% cost to you has NO CAP. You will need a Medicare Supplement along with a Part D plan OR a Medicare Advantage plan to help cap that 20% coverage. This will also help you to avoid a Part D penalty.

Answered by Melanie Rogers on May 4, 2026

Agent Licensed in FL, GA, OH & TX

Answered by Melanie Rogers Medicare Insurance Agent

Sharri Crawford · Answer

Original Medicare will only cover 80% of your Medical and there is no limit to Maximum out of pocket. This is why most people will either add a Medicare supplement or choose a Medicare advantage plan. These plans will give you security in knowing exactly what you pay for health services.

Answered by Sharri Crawford on June 2, 2026

Broker Licensed in NM

Answered by Sharri Crawford Medicare Insurance Agent

Andrew Kramer · Answer

No! Part A & B are not enough, unless you don't mind having to pay the 20% that Medicare does not cover for a hospitalization, and the Part A hospital deductible! Speak with a licensed, independent agent who can go over Advantage plans vs a supplement.

Answered by Andrew Kramer on May 4, 2026

Agent Licensed in FL

Answered by Andrew Kramer Medicare Insurance Agent

Geney Ruesga · Answer

Yes , Part A and Part B will only cover the cost of Medical at 80 percent. Then you have to find coverage to cover your 20 percent left over, so you choice would be a supplemental insurance to help you with that 20 percent.

Answered by Geney Ruesga on May 4, 2026

Broker Licensed in MS, AL, AZ & 7 other states

Answered by Geney Ruesga Medicare Insurance Agent

Jonathan Potter · Answer

You need to get at least a RX plan to be mostly covered. Medicare itself has a large deductible and then you pay a percentage of whatever the doctors charge. I would at least get on a medicare advantage plan so you don't have to pay for the RX plan separately and you will have a much lower financial risk if you do go to the hospital for something.

Answered by Jonathan Potter on May 4, 2026

Broker Licensed in UT, AZ, CA & 14 other states

Answered by Jonathan Potter Medicare Insurance Agent

Sandra Teel · Answer

In general, unless you are on the state Medicaid program with full coverage, I highly suggest you add additional coverage to Medicare Part A & B. It can be very complicated to determine what type of plan works best for your situation, so please reach out to me and we can talk more about it.

Answered by Sandra Teel on May 4, 2026

Broker Licensed in WV, AZ, CA & 13 other states

Answered by Sandra Teel Medicare Insurance Agent

Tony Spikes · Answer

Hello, it's Tony Spikes from Medicare Information Services. I got a question today, and I thought I'd share the answer with you as well.

Someone said, I've got Medicare A and B, do I need a supplement? And the answer is yes, of course.

Is just Medicare Part A and Part B enough coverage, or do I need supplemental insurance?

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Is just Medicare Part A and Part B enough coverage, or do I need supplemental insurance?

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