Medicare AEP vs OEP

AEP stands for Medicare Annual Enrollment Period and OEP stands for Medicare Open Enrollment Period. Depending on the context, OEP can refer to many other Medicare enrollment windows.

Find Medicare Plans in 3 Easy Steps

We can help find the right Medicare plans for you today

Difference Between Medicare AEP vs OEP

The Annual Enrollment Period otherwise referred to as AEP, is the time of year when a Medicare beneficiary can make changes to their current coverage. This enrollment window runs from October 15th to December 7th. Each September before AEP begins, the plan benefit changes for the next year are released, allowing Medicare beneficiaries to look around to ensure they are electing the plan that best fits their needs.

With Medicare Advantage plans and Medicare Part D Prescription Drug plans changing each year, premiums could increase, benefits can be changed, and prescription drug formularies can be changed.

Every year in September you will receive an Annual Notice of Change (ANoC) letter. This letter explains all the changes that will be affecting your plan in the upcoming year. The AEP gives you a chance to change if you are not happy with the future adjustments to your plan.

What You Can Do During the Medicare AEP

  • Drop a Medicare Advantage Plan and return to Original Medicare
  • Elect to change from one Medicare Advantage plan to a different one
  • Change from Original Medicare to an Advantage plan
  • Elect to change from one Medicare Part D prescription drug plan to another
  • Cancel your current Medicare Part D plan
  • Pick up a Medicare Part D plan if you currently do not have one

Any changes you make during the AEP will go into effect on January 1st of the following year.

What Can I Do During the Medicare Open Enrollment Period?

This depends on what OEP you’re referring to. If you’re talking about the AEP, then you can make changes to your current Medicare Advantage or Part D plan.

Those referring to the Medicare Advantage Open Enrollment Period can only make changes if they’re already enrolled in a Medicare Advantage plan.

If you’re referring to your Medicare Supplement Open Enrollment Period, then you can enroll in a Medicare Supplement plan without having to answer any health questions.

It’s important to note, you can enroll in a Medigap (Medicare Supplement) plan at any point during the year.

Find Medicare Plans in 3 Easy Steps

We can help find the right Medicare plans for you today

The only difference is if you do it outside your open enrollment window, you’ll have to answer Medicare Supplement underwriting questions.

How Many Changes Can I Make During the OEP?

Again, this depends on what Open Enrollment Period you’re referring to. If you’re making changes to your Advantage or Part D plan during the AEP, you can make as many changes as you want. The last change you make is what will stick and become effective January 1st of the following year.

If you’re referring to your Medigap OEP, you can also make as many changes as you want. Whichever plan you choose last is what plan you will be enrolled in. It will become effective the 1st of the following month, or as soon as your Part B is active. If you choose to make another change, and you’re still within your 6-month open enrollment window, your plan will become effective on the 1st of the following month.

If you’re talking about the Medicare Advantage Open Enrollment Period, you can only make one change during this enrollment window. So choose wisely the first time!

How to Get Help Understanding the Medicare OEP vs AEP

Medicare enrollment windows can be confusing, but speaking with a licensed insurance agent can help. Allow us to lend you our expertise to understand your choices and help you with the enrollment process. Give us a call to speak to a licensed agent, or complete our rate form to compare Medicare plans available in your area.

Enter ZIP Code

Enter ZIP Code

Enter your ZIP code to pull plan options available in your area.

Compare Plans

Compare Plans

Select which Medicare plans you would like to compare in your area.

Get Quote

Get Quote

Compare rates side by side with plans & carriers available in your area.

Kayla Hopkins

  • Content Editor

Kayla Hopkins is an accomplished writer and Medicare enthusiast serving as the Editor of Upon completing her Communications degree from Ohio University, Kayla dedicated her time to understanding the ever-evolving landscape of healthcare. With her extensive background as a Licensed Insurance Agent, she brings a wealth of knowledge and expertise to her writing.

6 thoughts on “Medicare AEP vs OEP

  1. Loved the article brief and concise. Making key points crystal clear between AEP vs. OEP and MAPD vs. Supplemental insurance.

  2. Ir you have clients with birthdays between October and January who are aging in can you sell them policies between 10/01 and 10/15?

    1. Hi Barbara! Yes, we can lock down the rates early for those aging in. However, the effective date of the policy won’t be until the 1st of the month they are 65 and their Part B is in effect.


Your email address will not be published. Required fields are marked *