The annual Open Enrollment Period (AEP or OEP) is the time each year when Medicare beneficiaries can add, change, or drop their Medicare Part D or Medicare Advantage plan coverage for the next year.

The OEP starts on October 15th and continues through December 7th of each year with coverage - or plan changes - taking effect on January 1st of the new year.

After the close of the OEP, most people will only have a limited opportunity to change their Medicare Part D plan coverage until the next Open Enrollment Period - for more information, please see: What are the Medicare Part D Special Enrollment Periods (SEP)?

The MA-OEP: Changing your Medicare Advantage plan after the AEP.

People enrolled in a Medicare Advantage plan are granted an additional time when they can change Medicare Advantage plans outside of the OEP or an SEP: the Medicare Advantage Open Enrollment Period (MA OEP). 

In short, the MA-OEP provides an additional opportunity for people to drop or change their Medicare Advantage plan coverage (MA or MAPD).

The Medicare Advantage OEP begins on January 1st and continues through March 31st with plan changes taking effect the first day of the month following the change.

As noted by Medicare, the MA-OEP allows people:

“enrolled in an MA plan, including newly MA-eligible individuals, to make a one-time election to go to another [Medicare Advantage] plan” - or to leave their Medicare Advantage plan, join a stand-alone Medicare Part D plan [PDP], and return to Original Medicare Part A and Part B. For example, an individual enrolled in an MA-PD plan may use the OEP to switch to: (1) another MA-PD plan; (2) an MA-only plan; or (3) Original Medicare with or without a PDP.

The [MA-OEP] will also allow an individual enrolled in an MA-only plan to switch to -- (1) another MA-only plan;

(2) an MA-PD plan; or (3) Original Medicare with or without a PDP.  [(Here is a link to our Medicare Part D plan finder: PDP-Finder.com to see stand-alone Medicare Part D plans in your area.]  However, this enrollment period [MA-OEP] does not allow for Part D changes for individuals enrolled in Original Medicare, including those with enrollment in stand-alone PDPs."

Practical note:  You may see a number of different terms that all describe the same enrollment period.
The Medicare Advantage and Prescription Drug Benefit Manual calls this time of year the "Annual Election Period (AEP)" and notes:

"Beginning in 2011, the AEP is from October 15 through December 7 of every year.  The AEP is also referred to as the “Fall Open Enrollment” season and the “Open Enrollment Period for Medicare Advantage AND Medicare prescription drug coverage” in Medicare beneficiary publications and other tools. MA organizations [and PDP plan sponsors] may use these descriptions of the AEP in their member materials, as well as in materials for prospective members."

So, you might find the annual Medicare Open Enrollment Period starting October 15^th and continuing through December 7^th described as the:

• OEP or Medicare Open Enrollment Period,
  
• AEP or annual Open Enrollment Period,
  
• Annual Enrollment Period (often seen on a Medicare plan's printed application form),
• Annual Election Period,
• Annual Coordinated Election Period,
• Medicare Fall Open Enrollment Period (OEP),
• Fall Open Enrollment season, or
• Open Enrollment Period for Medicare Advantage and Medicare prescription drug coverage.

Again, all these terms refer to the same (October 15 through December 7) enrollment period.

Important:  When completing a printed enrollment application during the annual Open Enrollment Period, choose the "AEP" when asked about the enrollment period.

Although we use the term annual Open Enrollment Period interchangeably with AEP (Annual Enrollment Period or Annual Coordinated Election Period), when you are enrolling in a Medicare plan using a paper application, you may see "AEP" as an enrollment period option - meaning the annual Open Enrollment Period.

On your printed enrollment application, you may see a few other abbreviations or acronyms for different enrollment periods, such as: IEP (Initial Enrollment Period), MA-OEP (Medicare Advantage Open Enrollment Period), and SEP (Special Enrollment Period).  Do not confuse these terms with your "AEP".

For more information about completing a printed Medicare plan enrollment application, please see our article:
"Seven tips for successfully submitting your Medicare Part D or Medicare Advantage plan's printed enrollment form" found at: Q1FAQ.com/24

Sources include:
Medicare Managed Care Manual, Chapter 2 - Medicare Advantage Enrollment and Disenrollment, Updated: August 19, 2011 (Revised: November 16, 2011, August 7, 2012, August 30, 2013,August 14, 2014, July 6, 2015, September 1, 2015, September 14, 2015, December 30, 2015, May 27, 2016, August 25, 2016,June 15, 2017, July 31, 2018, August 12, 2020, & August 15, 2023)

Medicare Prescription Drug Benefit Manual, Chapter 3 - Eligibility, Enrollment and Disenrollment, Updated: August 19, 2011, (Revised: November 16, 2011, August 7, 2012, August 30, 2013, August 30, 2014, July 6, 2015, September 1, 2015, September 14, 2015, December 30, 2015, May 27, 2016, August 25, 2016, June 15, 2017, July 31, 2018, August 12, 2020, & August 15, 2023)