Skip to main content

BEACON Senior News - Western Colorado

What's the difference between Medicare's open enrollment periods?

Sep 30, 2023 04:49PM ● By National Council on Aging

This article was originally posted by the National Council on Aging. Read the original article here.

For the more than 64 million Americans enrolled in Medicare, one of the first signs of fall each year is the arrival of the Medicare & You handbook. This valuable guide is a signal that two very important annual enrollment periods are just around the corner: Medicare’s Open Enrollment Period and the Medicare Advantage Open Enrollment. 

This guide explains the actions you can take during each enrollment period. Knowing more about these two distinct enrollment opportunities can help you make informed decisions about your health and drug coverage.

At a glance, there are two main ways these two enrollment periods differ:

  • They are held at different times of the year. Medicare’s Open Enrollment Period is from October 15 to December 7. The Medicare Advantage Open Enrollment is from January 1 to March 31.
  • They both offer different opportunities for adjusting your coverage. During Medicare’s Open Enrollment Period (AEP or OEP), Medicare beneficiaries can make a wider range of changes. The Medicare Advantage Open Enrollment period gives people with Medicare Advantage plans one additional chance to change Medicare Advantage plans or switch to Original Medicare.

How does Medicare’s annual Open Enrollment Period work?

This annual enrollment period, from October 15 to December 7, is for anyone enrolled in Medicare Parts A and/or B, including those who may already be enrolled in a Medicare Advantage (Part C) or Part D. As a Medicare beneficiary, you can join, switch or drop a health and/or drug plan. You can also:

  • Change from Original Medicare to a Medicare Advantage Plan and vice versa
  • Switch from one Medicare Advantage Plan to another
  • Join or switch Medicare drug plans
  • Drop your Medicare drug coverage completely
  • Switch from a Medicare Advantage Plan that doesn’t offer drug coverage to one that does and vice versa

You don’t have to change your coverage if your current plans meet your medical and budgetary needs, but the Centers for Medicare & Medicaid Services (CMS) recommends all Medicare beneficiaries assess their coverage annually.

Open enrollment changes become effective on January 1, as long as you meet the December 7 deadline.

How does the annual Medicare Advantage Open Enrollment Period work?

This period, from January 1 to March 31, is for people who are already enrolled in a private Medicare Advantage plan. It gives Medicare Advantage (MA) plan holders an additional opportunity to make changes. You can only change plans once during this enrollment period. Here are some actions you can take: 

  • If you’re in a Medicare Advantage Plan, you can switch to another Medicare Advantage Plan (with or without drug coverage)
  • You can drop your Medicare Advantage Plan and return to Original Medicare. 
  • You’ll also be able to join a separate Medicare drug plan

Things you can’t do:

  • Switch from Original Medicare to a Medicare Advantage Plan
  • Join a Medicare drug plan if you’re in Original Medicare
  • Switch from one Medicare drug plan to another if you’re in Original Medicare

Your coverage will start the first day of the month after you apply to join the plan.

The National Council On Aging has more information and experts you can talk to about Medicare enrollment. You’ll also find Medicare resources, information and tools at You can also explore coverage options by calling 1-800-MEDICARE (1-800-633-4227) or visiting

Finally, you can talk directly to a licensed Medicare broker or contact the State Health Insurance Assistance Program (SHIP) for free, unbiased advice. 

  • Mesa County SHIP: 970-243-9839, x 1
  • Montrose & Delta SHIP: 970-765-3129 
You might also like these articles: 
3 mistakes that can cost Medicare beneficiaries a fortune

3 mistakes that can cost Medicare beneficiaries a fortune

Do these three things and your Medicare will do the very thing it’s designed to do: save you money on your health care. Read More » 

What are Medicare savings programs

What are Medicare savings programs?

If you have limited income and assets, Medicare Savings Programs (MSPs) can help cover your Medicare costs. Read More »