Can You Keep Medicare and Marketplace Insurance?

Turning 65 brings a flood of mail, a barrage of phone calls, and a lot of confusion about your healthcare options. If you currently get your health coverage through the Affordable Care Act (ACA) exchange, you are likely wondering how the transition works. A common question we hear is about mixing coverage: what happens with Medicare and marketplace insurance when you reach retirement age?

The short answer is that while you technically can keep an existing marketplace plan after your Medicare starts, it is almost always a terrible financial decision. Transitioning from marketplace coverage to Medicare causes confusion that can trigger permanent financial penalties, surprise tax bills, and massive coverage gaps.

At Rebel Rates, our goal is to give you the facts without the sales pitch. We are an independent site, not affiliated with or endorsed by the U.S. government or the federal Medicare program. In this cornerstone guide, we will walk you through the 2026 and 2027 rules for Medicare and marketplace insurance, show you the exact math on late-enrollment penalties, and give you a step-by-step checklist to drop your exchange coverage cleanly.

Can You Keep an ACA Marketplace Plan After Medicare?

The rules regarding Medicare and marketplace insurance are split into two distinct categories: buying a new plan versus keeping an old one.

The Legality Rule for Buying New Coverage

By law, it is illegal for an insurance company or a broker to sell you a marketplace health insurance plan if they know you are already enrolled in Medicare. This anti-duplication law exists to protect seniors from being sold redundant, overpriced coverage they do not need. If you already have Medicare Part A (hospital insurance) or Part B (medical insurance), you cannot go onto HealthCare.gov or your state exchange to buy a new policy.

The Transition Rule for Existing Coverage

If you already have a marketplace plan before you turn 65, the rules shift. You can technically keep your existing marketplace plan when your Medicare starts. The exchange will not automatically cancel your policy the day you turn 65. However, keeping it triggers a domino effect of financial consequences.

Once your Medicare Part A coverage begins, you immediately lose your eligibility for marketplace premium tax credits and reduced cost-sharing. You are no longer considered uninsured or underinsured by the federal government. This means if you decide to keep your marketplace plan alongside Medicare, you will have to pay the full, un-subsidized sticker price for the ACA plan.

Why Tax Subsidies End Once You Become Medicare-Eligible

Most people on the ACA marketplace rely on Advance Premium Tax Credits (APTC) to make their monthly premiums affordable. These subsidies are based on your estimated income for the year. But the moment you become eligible for premium-free Medicare Part A, the IRS rules state that you no longer qualify for these tax credits.

Let us look at a real-world scenario to understand the financial impact. Imagine you are 64 years old, and your full marketplace premium is $800 per month. Because of your income, you receive a $600 monthly tax credit, bringing your out-of-pocket cost down to $200 per month. You turn 65 in May, and your premium-free Medicare Part A begins on May 1.

If you do not cancel your marketplace plan, you will lose that $600 subsidy starting in May. Your marketplace premium will instantly jump to the full $800 per month. Furthermore, Medicare premiums are not age-rated. Unlike marketplace plans, which can charge older adults up to 3 times more than younger adults, everyone pays the same standard Part B base premium. In 2026, the standard Medicare Part B premium is $202.90 per month. Paying $800 for an un-subsidized ACA plan when you could be paying $202.90 for Medicare Part B makes zero financial sense for most retirees.

Tax Reconciliation: The Surprise IRS Bill for Overlapping Coverage

What happens if you simply forget to cancel your marketplace plan and keep receiving subsidies after your Medicare starts? The federal government will eventually find out, and you will pay for it during tax season.

When you file your federal income taxes, you must use IRS Form 1095-A to reconcile the advance tax credits you received during the year. If the IRS sees that your premium-free Medicare Part A started in May, but you continued to take marketplace subsidies through December, they will claw back that money. You will be forced to repay all the tax subsidies you received for those overlapping months. In our previous example of a $600 monthly subsidy, an eight-month overlap would result in a surprise tax bill of $4,800.

The Danger of Medicare Part B Late-Enrollment Penalties

Losing your subsidies is not the only financial danger. If you decide to keep your marketplace insurance instead of enrolling in Medicare when you are first eligible, you will face severe, permanent late-enrollment penalties.

Many people mistakenly believe that their marketplace plan counts as employer-sponsored coverage. It does not. Only group health insurance from a current employer (where you or your spouse actively work) allows you to delay Medicare without penalty. Marketplace insurance does not qualify you for a Special Enrollment Period.

If you delay enrolling in Medicare Part B, you will face a late-enrollment penalty of 10% for each full 12-month period you delayed. This penalty is added to your monthly Part B premium for the rest of your life.

Calculating the Part B Penalty for 2026

Let us break down the exact math using the official 2026 figures. The standard Medicare Part B premium in 2026 is $202.90 per month. If you delayed Part B for three full years because you thought your marketplace plan was sufficient, you would owe a 30% penalty.

• Standard 2026 Premium: $202.90
• 30% Penalty: $60.87
• Your Total Monthly Premium: $263.77

You will pay this inflated premium every month for as long as you have Medicare. Over a 20-year retirement, that single mistake would cost you over $14,000 in unnecessary penalty fees.

Is Marketplace Insurance Considered Creditable for Medicare Part D?

Prescription drug coverage (Medicare Part D) has its own set of rules and penalties. If you delay enrolling in a Part D plan, you will pay an extra 1% of the national base beneficiary premium for each month you delay without having creditable prescription drug coverage.

Many competing articles state a blanket rule that marketplace plans do not protect you from Medicare penalties. This is not entirely accurate when it comes to Part D. Some marketplace plans actually do offer creditable drug coverage—meaning the coverage is expected to pay, on average, at least as much as standard Medicare prescription drug coverage.

However, you cannot just guess if your plan is creditable. You must verify this annually. Your marketplace insurance company is required to send you a written notice every September telling you whether your plan's drug coverage is creditable. If you keep a creditable marketplace plan and delay Part D, you will not face the 1% penalty. But if your plan is not creditable, or if you lose that letter and cannot prove it, that 1% monthly penalty will accrue quickly.

How the New $2,000 Part D Drug Cap Compares to Exchange Plans

Even if your marketplace plan offers creditable drug coverage, transitioning to Medicare is now vastly superior for prescription needs due to recent legislative changes. Thanks to the Inflation Reduction Act (IRA), starting in 2025 and continuing into 2026 and 2027, Medicare Part D out-of-pocket drug costs are capped at $2,000 annually.

Compare this to a standard ACA marketplace plan. Many marketplace plans have out-of-pocket maximums that can exceed $9,000 for an individual. If you take expensive brand-name medications or specialty drugs, staying on a marketplace plan could cost you thousands of dollars more per year at the pharmacy counter. The new $2,000 Part D cap makes Medicare the clear winner for anyone with high prescription needs. For more details on drug costs, you can read our guide on the Medicare Part D Deductible for 2026 and 2027.

The Exception: When You Have to Pay for Medicare Part A

There is one major exception to the rule about dropping marketplace coverage. The advice to cancel your exchange plan assumes you qualify for premium-free Medicare Part A. You get premium-free Part A if you or your spouse worked and paid Medicare taxes for at least 40 quarters (about 10 years).

But what if you did not work enough quarters? If you have fewer than 30 quarters of Medicare-covered employment, the Part A premium is $565 per month in 2026. If you have 30 to 39 quarters, it is $311 per month in 2026.

If you do not qualify for premium-free Part A, the rules change entirely. You are not forced to drop your marketplace plan, and you do not automatically lose your subsidies. You can legally choose to delay Medicare and keep your marketplace plan with advance premium tax credits. For many seniors facing a $565 monthly Part A bill, keeping a heavily subsidized marketplace plan is the most affordable choice.

The Part A Late Enrollment Penalty

If you choose this route, you must be aware of the Part A late enrollment penalty. If you have to pay a premium for Part A and you delay it, your monthly premium may go up 10%. Unlike the Part B penalty, which lasts forever, you will only have to pay this higher Part A premium for twice the number of years you did not sign up. If you delayed for two years, you would pay the 10% penalty for four years.

What Happens to Your Spouse or Dependents?

Transitioning from Medicare and marketplace insurance gets complicated if you are on a family plan. What happens if you turn 65, but your spouse is only 62 and your child is 24? You cannot simply cancel the entire family policy.

In this scenario, you must log into HealthCare.gov (or your state's exchange portal) and remove only yourself from the policy. This is known as splitting the policy. Your younger spouse and dependents will remain on the marketplace plan, and their premium tax credits will be recalculated based on the new household size and the fact that you are no longer on the policy.

It is crucial to handle this correctly. Do not cancel the whole plan, or your family will be left uninsured. Update your application to indicate that you are now eligible for Medicare, which will remove you from the coverage while keeping your family protected.

Coordination of Benefits and Coverage Gaps to Avoid

If you accidentally overlap your Medicare and marketplace insurance for a few months, you might assume you have double coverage and can use both. This is a dangerous assumption due to the rules regarding coordination of benefits.

When you have Medicare and another type of insurance, rules determine which insurance pays first (the primary payer) and which pays second (the secondary payer). If you have a marketplace plan and Medicare, Medicare is almost always the primary payer. This means Medicare pays its share of the bill first.

Here is the trap: many marketplace plans will refuse to pay anything as a secondary payer if they know you have Medicare. If you go to the hospital and you have not paid your Medicare Part A deductible—which is $1,736 per benefit period in 2026—you might assume your marketplace plan will cover it. It likely will not. You will be stuck paying the $1,736 deductible out of pocket, while also paying the full un-subsidized premium for a marketplace plan that is providing zero benefit.

Step-by-Step Guide to Dropping Exchange Coverage Cleanly

To avoid penalties, tax bills, and overlapping coverage, you must time your transition perfectly. Here is your actionable checklist for moving from marketplace insurance to Medicare.

• Step 1: Confirm your Medicare start date. Your Medicare coverage typically begins on the first day of the month you turn 65. If your birthday is on the first of the month, your coverage starts the first day of the prior month.
• Step 2: Enroll in Medicare early. Your Initial Enrollment Period begins three months before your 65th birthday month. Do not wait until your birthday month to apply.
• Step 3: Choose your supplemental coverage. Decide whether you want Original Medicare with a Medigap policy and a standalone Part D plan, or a Medicare Advantage plan. You can compare options in our Health Insurance guides.
• Step 4: Contact the Marketplace 14 days in advance. You must contact your marketplace provider to cancel your coverage at least 14 days before your Medicare coverage begins. If your Medicare starts June 1, you must cancel your marketplace plan by mid-May to ensure it ends on May 31.
• Step 5: Keep your cancellation confirmation. Always get a confirmation number or letter proving you canceled your marketplace plan. You may need this if there is a billing error later.

Comparing the Costs: Marketplace vs Medicare in 2026

To make the financial reality clear, let us look at a side-by-side comparison of costs and potential penalties for the year 2026.

Common Mistakes When Transitioning to Medicare

Even with the best intentions, seniors frequently make critical errors when dealing with Medicare and marketplace insurance. Here are the most common mistakes to avoid:

Assuming Auto-Enrollment Applies to Everyone

If you are already receiving Social Security benefits, you will be automatically enrolled in Medicare Parts A and B when you turn 65. However, if you have not started claiming Social Security, you must actively sign up for Medicare. Many people on marketplace plans assume they will be automatically transitioned and miss their Initial Enrollment Period entirely, triggering the 10% Part B penalty.

Ignoring the 14-Day Cancellation Rule

Marketplace plans do not cancel retroactively. If you call on June 5th to cancel a plan because your Medicare started on June 1st, the marketplace will likely bill you for the entire month of June at the full, un-subsidized rate. Always give at least 14 days notice.

Misunderstanding Employer Coverage

We cannot stress this enough: marketplace insurance, COBRA, and retiree health plans are not considered active employer coverage. Only insurance based on current, active employment allows you to delay Medicare without penalty. If you are unsure about your coverage type, read our guide on the Cost of Employer Family Health Insurance to understand group plans better.

A Detailed Look at Deductibles: Medicare vs ACA

When deciding whether to keep a marketplace plan (if you do not qualify for premium-free Part A), you must compare the deductibles. In 2026, the Medicare Part B annual deductible is just $283. Once you meet that small deductible, Medicare typically pays 80% of approved medical costs.

In contrast, many ACA Bronze or Silver plans have deductibles ranging from $3,000 to $7,000. If you have a chronic condition that requires frequent doctor visits, the low $283 Part B deductible will save you thousands of dollars early in the year compared to a marketplace plan. Understanding the Deductible vs Out-of-Pocket Max is crucial when making this comparison.

How to Compare Options on Rebel Rates

Navigating the transition from Medicare and marketplace insurance requires careful timing and a clear understanding of the 2026 costs. Making the wrong choice can lead to lifetime penalties and thousands of dollars in surprise tax bills. Do not let the confusion cost you your hard-earned retirement savings.

If you are approaching 65 or need to evaluate your current coverage, you need transparent, accurate numbers without the pressure of a commissioned sales agent breathing down your neck. At Rebel Rates, our brand promise is simple: No BS, just the lowest rates.

You can easily compare your health insurance and Medicare options using our independent tools. We provide the exact figures you need to make an informed decision for your family. Ready to see the real numbers for your specific situation? Compare Health Insurance quotes today and secure the right coverage for your future.