Medicare enrollment and changing plans
Need to enroll in Original Medicare? Changing plans? There’s a path just for you. Understand timing and coverage options to get where you need to go.

When can I enroll in Original Medicare or apply for more coverage?
You can enroll in Original Medicare starting three months before you turn 65, unless you qualify earlier. After you’re enrolled, you can look into adding to your coverage with a Medicare Advantage (Part C) plan, a Medicare prescription drug (Part D) plan, or a Medicare Supplement (Medigap) plan.
Enrolling in Original Medicare (Parts A and B) for the first time.
Enrollment in Original Medicare may or may not be automatic – depending on your situation.
You’re automatically enrolled if you already receive Social Security or Railroad Retirement Board benefits, or become eligible early due to disability. Otherwise, you’ll need to enroll yourself during your Initial Enrollment Period (IEP).
You can enroll in Part A, Part B, or both. You don’t have to enroll in Part B right away, because you’ll be charged a premium. Just remember that if you choose to wait to enroll in Part B, you’ll be charged a late enrollment penalty, and Part B coverage will cost you more.
You can enroll in Original Medicare online at the Social Security website or by calling or visiting your local Social Security office.

Can I get additional coverage beyond Original Medicare right away?
Yes, as soon as you enroll in Original Medicare Part A and/or Part B. How much time you have to get additional coverage depends on when you enroll in Original Medicare.
You have to have both Part A and Part B to enroll in a Medicare Advantage (Part C) plan. For a Medicare prescription drug (Part D) plan, you only need Part A or Part B.
First-time Original Medicare (Part A and Part B) enrollment
When is the IEP?
The Initial Enrollment Period is a 7-month window around your 65th birthday. It covers your birth month, plus the 3 months before and the 3 months after.
When can I get additional coverage?
After you enroll in Original Medicare and during your IEP, you can add a Medicare Advantage (Part C) plan or a Medicare prescription drug (Part D) plan.
When is the GEP?
The General Enrollment Period is available to you if you didn’t sign up during your IEP. The GEP runs January 1 to March 31 each year.
When can I get additional coverage?
If you enroll in Original Medicare during the GEP, you can add a Medicare Advantage (Part C) plan or a Medicare prescription drug (Part D) plan between April 1 and June 30 of the same year.
When is the SEP?
The Special Enrollment Period lets you enroll in Original Medicare outside of your IEP due to certain life changes. For example, you might wait to enroll if you’re still working. Timing depends on when those life changes happen.
What if I retire after I’m 65?
You have 8 months to enroll in Original Medicare without a late penalty. The 8-month period begins after the month your employment or employer coverage ends, whichever comes first. This is also true if you are covered under your spouse’s employer coverage.
When can I get additional coverage?
If you want Medicare Advantage (Part C) plan or Medicare prescription drug (Part D) plan after an SEP, you need to act quickly. You have just 2 months after the month your employment or employer coverage ends to enroll in a Medicare Advantage (Part C) or Medicare prescription drug (Part D) plan – but you have to enroll in Original Medicare first.

How do I know if I should change plans?
Health care and budget needs change over time. If your current plan isn’t meeting your needs, you can switch to a different plan or even a different type of Medicare coverage.1
Medicare Advantage and Medicare prescription drug plans send information to members every fall. This is called the Annual Notice of Changes (ANOC). The ANOC explains upcoming updates to the plan’s benefit coverage, costs, or service area for the next plan year. When looking at your current and future needs, the ANOC can help you decide if you need a different plan.
- Have there been changes to your personal health needs?
- Will your benefits change next year?
- If your plan uses provider networks, will your provider(s) still be in your plan’s network next year? If you need to see a specialist, do you need a referral?
- Is your medication still on your plan’s drug list (formulary)? Will the plan’s network of pharmacies make it convenient for you to get your drugs?
- Does the plan offer other benefits that are important to you, such as dental and vision care or a fitness benefit?
- Will your monthly premium payment be higher, the same or lower?
- If your plan uses pharmacy networks, will your pharmacy still be in your plan’s network?
- Will your medication still be on the plan’s drug list (formulary)? Is any of your medication changing to a higher drug tier and might cost more?
- Will there be changes to your deductible, copay or coinsurance amounts? Will you be paying more or less than you are now?

When can I change my plan or apply for additional coverage?
Applying for additional coverage (Medicare Advantage, Medicare Supplement and Medicare Prescription Drug plans) for the first time
After you enroll in Original Medicare, you can also apply for a plan with additional coverage through private insurance companies like UnitedHealthcare.
Key enrollment periods for changing your coverage
When is the AEP?
The Medicare Annual Enrollment Period is October 15 to December 7 every year.
What can I do?
During AEP you can join, switch or drop a plan. For example, you can:
- Enroll in a Medicare Advantage (Part C) or Medicare prescription drug (Part D) plan.
- Switch to a different Medicare Advantage or Medicare prescription drug plan.
- Drop a Medicare Advantage plan and go back to Original Medicare (Parts A and B). Then you could also apply for a Medicare Supplement plan.
- Replace a Medicare Advantage plan with a standalone Medicare prescription drug plan.
If you don’t make any changes during AEP, your current plan will automatically renew the next year.
When is the SEP?
The Special Enrollment Period (also known as a Special Election Period) lets you change or add Medicare Advantage (Part C) or Medicare prescription drug (Part D) coverage outside of AEP due to certain qualifying events. Timing depends on when those qualifying events happen.
What can I do?
If you qualify, you can return to Original Medicare (Parts A & B) or join, change or drop a Medicare Advantage (Part C) or Medicare prescription drug (Part D) plan. If you choose to go back to Original Medicare in this qualifying event, you can also apply for a Medicare Supplement plan. There are many types of qualifying events, including moving into or out of a care facility, or moving out of your current plan’s service area.
When is the Medicare Supplement Open Enrollment period?
The Medicare Supplement Open Enrollment period is the six-month period that starts the first month in which you are age 65 or older and enrolled in Medicare Part B. If your initial enrollment in Part B is before age 65, you have a second six-month Open Enrollment period beginning the month you turn 65. Some states may have additional open enrollment periods, and there may be other situations in which your acceptance may be guaranteed.
When can I apply?
You can apply for a Medicare Supplement insurance plan any time during the year.2
What can I do?
You can add a Medicare Supplement plan and/or a standalone Medicare Prescription Drug (Part D) plan to Original Medicare (Parts A & B). You cannot have a Medicare Supplement plan and a Medicare Advantage (Part C) plan at the same time.
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