Key Takeaways
- If you cancel or disenroll from Medicare Part B, you may have to pay a late enrollment penalty to reenroll, especially if there’s a gap in your coverage.
- You can reenroll in Medicare Part B during several enrollment periods, including the general enrollment period (January 1 through March 31), or a special enrollment period if eligible.
- To qualify for Medicare Part B, you generally need to be age 65 years or older, or have a qualifying disability or medical condition and receive Social Security disability payments.
Over time, your needs may change and require you to swap Medicare plans. Each year, you have up to three opportunities to switch your Medicare coverage and reenroll in Original Medicare, which includes Part A and Part B.
If you’ve disenrolled from or canceled your Medicare Part B coverage, you may have to pay a costly late enrollment penalty to reenroll. This is especially true if you have a gap in coverage.
If you’re looking to reenroll in Medicare Part B, you can:
- go to the Social Security Administration (SSA) website
- complete form CMS-40B, the application for enrollment in Medicare Part B (medical insurance). The form is also available in Spanish.
- mail all required documents to the Social Security office. Be sure to include all required official or certified documents to ensure a seamless process.
If you are reenrolling in Part B and you already have Part A, you may not be able to enroll online. If you can’t, the SSA recommends performing one of the following steps:
- Apply on the SSA website, completing and submitting all required forms, along with evidence of your workplace health plan.
- Fax or mail all required documentation to your local Social Security office.
If you did not have Medicare Part B due to a workplace insurance plan, you may have to prove coverage to avoid paying late enrollment fees. You can do this by completing form CMS-L564, the request for employment information. A Spanish version is also available. Upon approval, you’ll be granted a special enrollment period. During this time, you can enroll in Medicare Part B without penalty.
Missed Part B premium payments
If you were disenrolled from your Medicare Part B plan for missing premium payments, you have around a 2-month grace period to pay what’s owed. If you don’t pay back the premiums within the allotted time, you’ll have to reenroll during the next general enrollment period, which runs from January 1 through March 31 each year.
Medicare’s Good Cause policy
You can also ask for reinstatement under the Medicare Good Cause policy. If you prove there’s “good cause” (or reason) for not paying premiums — typically an emergency, chronic illness, or other related situation — you’ll still have to pay all owed premiums within a specified period of time to resume coverage.
Medicare has three main enrollment periods:
- initial enrollment
- general enrollment period (also called Medicare Advantage open enrollment)
- special enrollment
The initial enrollment period is a 7-month time frame. It includes:
- the 3 months before your 65th birth month
- your birth month
- 3 months after your birth month
It’s recommended that you enroll during the first 3 months of initial enrollment so your coverage will begin earlier and you’ll avoid delays.
If you do not sign up for Medicare Part B when you’re first eligible, you run the risk of having to pay a late enrollment penalty for as long as you have Part B insurance.
When your initial enrollment period ends, if you haven’t enrolled in Medicare, you may have the opportunity to enroll during a special enrollment period without having to pay a penalty if approved.
If you’re already covered through a workplace plan, or if you or your spouse has a disability, you can sign up for Part B at any time.
An 8-month special enrollment period to enroll in Part B also comes into play 1 month after your employment or workplace insurance plan ends. You can even qualify for a special enrollment period if you’re a volunteer in another country.
If you miss your initial enrollment and aren’t eligible to sign up during a special enrollment period, you can sign up for Medicare Part B during the general enrollment period. This occurs from January 1 through March 31 each year.
The caveat to this enrollment period is that you may have to pay higher premiums on the plan for late enrollment.
Enrollment periods for Medicare
- Medicare Advantage open enrollment — January 1 through March 31: During this period, you can switch from one Medicare Advantage plan to another or go back to Original Medicare.
- Medicare open enrollment period — October 15 through December 7: During this time, you can switch from a Medicare Advantage (Part C) plan back to Original Medicare. You can also change Part C plans or add, remove, or change a Medicare Part D (prescription drug) plan.
- Special enrollment period — 8 months following a qualifying event: If you qualify, you may be granted this 8-month window to reenroll in Original Medicare or change your Medicare coverage after a significant life event, such as a divorce or move.
Medicare Part B covers two main types of services:
- outpatient care that’s medically necessary
- preventive services
Medically necessary services include those needed to diagnose and treat a medical condition. This can include:
- annual visits to your healthcare practitioner
- other outpatient services
- visits to the emergency room
Preventive services include treatments and screenings to detect and prevent illnesses.
Other services covered under Part B include:
- clinical research
- outpatient surgeries
- durable medical equipment
- mental health services
To qualify for Medicare Part B, you must satisfy at least one of these main eligibility requirements:
- You’re 65 years old or over.
- You have a disability and receive disability payments.
- You have end stage renal disease (ESRD).
- You have amyotrophic lateral sclerosis (ALS).
Though you’re unable to use the plan benefits until the day you turn 65 years old, you’re eligible to enroll:
- 3 months before your 65th birthday
- on your 65th birthday
- 3 months after your 65th birthday
You’re also qualified to enroll in Medicare Part B if you have a disability and are receiving Social Security disability payments. This applies even if you’re not 65 years old.
Some of the more common qualifying disabilities include:
- neurological disorders
- cardiovascular disorders
- mental disorders
- blood disorders
- sensory disorders
People ages 65 years or over will usually qualify for Medicare coverage.
If your workplace participates in a group health plan, you have the option to opt out of or disenroll from Medicare plans. This is often the case for Medicare Part B.
You can reenroll in a Medicare plan later, but this can result in late enrollment penalty fees and may require proof of alternative coverage.
Before making changes to your insurance plans, make sure you understand the benefits and risks of doing so. While it’s helpful to have options, make sure they best suit your needs.



