Most people who are eligible for Medicare choose to use its medical care coverage and benefits once they turn 65. But for some, choosing different coverage or even forgoing coverage altogether are options to explore. The question is, when you turn 65, do you have to sign up for Medicare?
Deferring Medicare coverage is uncommon, but it is possible. Let’s look at what is and isn’t required for Medicare, why some may defer coverage and how to do it.
Is Medicare mandatory at age 65?
No, Medicare is not mandatory. However, many people have spent the better part of their careers paying into the program, and there are good reasons to accept it. Medicare helps cover essential health services, and affordable access to medical care becomes even more important as you age.
Opting out of Medicare can be tricky, especially if you receive Social Security or Railroad Retirement Board benefits before turning 65. If you’re already receiving these benefits, you will be automatically enrolled in Original Medicare when you become eligible.
Can you opt out of Medicare?
Yes, you can choose to opt out of Medicare. However, there’s a difference between delaying enrollment and declining Medicare coverage altogether.
There are several reasons to delay enrolling in Medicare. One involves monthly premium costs. If you’re still working past 65, it may be cheaper to keep your employer-sponsored health plan. In this situation, if your health insurance is provided through a large-group insurer that covers everything Original Medicare does, you may be able to defer Medicare enrollment.
Declining Medicare coverage is something else entirely, and it can be complicated. If you choose to decline Medicare, you’ll lose all your Social Security or Railroad Retirement Board benefits and will be required to return all payments you’ve received.
How to opt out of Medicare
To opt out of Original Medicare coverage, you need to provide written, signed consent. To start this process, contact the Social Security Administration, which processes Medicare applications. If you were automatically enrolled in Original Medicare, your welcome packet will have deferment instructions for you. This includes sending your Medicare ID card back. If you keep your card, you’ll have to begin paying Part B premiums.
What can happen if you don’t enroll in Medicare at 65
Medicare is comprised of different parts covering specific types of health care services. It’s important to know how these parts work, so you can understand how each may be affected if you choose to opt out of Medicare. Original Medicare, which is what you become eligible for when you turn 65, includes Part A and Part B – other parts are optional. When you delay enrollment, if or how much you might be penalized depends on which part of Medicare is affected.
Medicare Part A (Hospital coverage) penalties
You become eligible for Part A coverage after you (or your spouse or partner) have paid into Medicare for 10 years throughout your career. For most people, Part A is automatic and premium-free when you turn 65.
When you opt out of enrolling in Medicare Part A, you may face a penalty depending on the reason why you chose to do so. For instance, if you don’t qualify for premium-free Part A and decide to opt out with no cause, your monthly Part A premium can increase by up to 10%, and you’ll have to pay this higher amount for twice as long as you went without being enrolled. This means that if you delay enrollment by three years, you’ll pay an additional 10% for your Part A premium for the first six years.
Medicare Part B (Medical coverage) penalties
Part B includes monthly premium payments, which were $185 in 2025. This amount is based on your income listed on your federal tax return. While you can defer Part B coverage, doing so may result in robust penalties. It depends on your situation, but if you decide to enroll in Part B later and don’t qualify for a Special Enrollment Period, you may have to pay a late enrollment penalty. This penalty will last throughout your time as a Medicare beneficiary.
The penalties for opting out of Part B can be more severe than that of Part A, because they’re cumulative and lasting. Each year you don’t sign up for Medicare, you must pay a 10% penalty for each full 12-month period you waited to sign up after you were first eligible. And this penalty doesn’t go away – it affects you for the duration that you’re enrolled in Medicare.
This means that if you defer enrollment for two years, your monthly premium will be 20% higher than what you would have paid when you were first eligible.
Medicare Part D (Prescription drug coverage) penalties
Part D coverage is not covered by Original Medicare – it’s optional through a Part D prescription drug plan or a Medicare Advantage plan. Medicare Advantage plans (Part C) are required to provide Part A and B coverage, and if a plan also includes Part D, you have all your coverage options in one place.
While Part D isn’t technically mandatory, you may still be subject to a penalty for signing up late. If you don’t join a Medicare drug plan when you are first eligible or go 63 days without creditable drug coverage, you’ll pay an extra 1% for each month you went without prescription drug coverage. This means that if you don’t enroll for six months, you’ll have to pay a 6% late enrollment penalty in addition to your monthly plan premium for the entire time you have Medicare Part D coverage.