"There is one AEP enrollment/disenrollment choice available for use during this period. An enrollment/disenrollment election cannot be changed after the end of the AEP." (p.21 PDP Manual)However, the Medicare Managed Care Manual (for Medicare Advantage plans), Chapter 2 - Medicare Advantage Enrollment and Disenrollment (2024), Section 30.1 - Annual Election Period (AEP), states this information slightly differently:
"During the AEP, MA eligible individuals may enroll in or disenroll from an MA plan. The last enrollment request made, determined by the application date, will be the enrollment request that takes effect (refer to §60.1 for information on multiple transactions)." (p.30 MA Manual)Strangely enough, it would seem that you can have multiple MA applications with the application having the newest application date as being the chosen plan for January 1st. Whereas, it does not appear the PDPs follow the same convention.
“Multiple transactions occur when CMS receives more than one enrollment (or disenrollment) request for the same individual with the same effective date in the same reporting period. An individual may not be enrolled in more than one PDP at any given time (however, an individual may be simultaneously enrolled in a cost plan and a separate PDP plan or in certain MA plan types and a separate PDP plan).The MA Enrollment and Disenrollment manual has similar text in section 60.1 – Multiple Transactions:
Generally, the last enrollment request the beneficiary makes during an enrollment period will be accepted as the PDP into which the individual intends to enroll. If an individual requests enrollment in more than one PDP for the same effective date and with the same application date, the first transaction successfully processed by CMS will take effect. Because simultaneous enrollment in a PDP and certain MA plan types is permitted, CMS systems will accept such enrollments.
Generally, given the use of the application date to determine the intended enrollment choice, retroactive enrollments will not be processed for multiple transactions that reject because enrollment requests have the same application date.” (p.128, PDP Manual)
“Multiple transactions occur when CMS receives more than one enrollment request for the same individual with the same effective date in the same reporting period. An individual may generally not be enrolled in more than one MA, cost, HCPP or PDP plan at any given time (however, an individual may be simultaneously enrolled in a cost plan and a separate PDP plan or in certain MA plan types and a separate PDP plan).
Generally, the last enrollment request the beneficiary makes during an enrollment period will be accepted as the plan into which the individual intends to enroll. If an individual elects more than one plan for the same effective date and with the same application date, the first transaction successfully processed by CMS will take effect. Because simultaneous enrollment in certain MA plan types and a separate PDP is permitted, CMS systems will accept both enrollments.
Generally, given the use of the application date to determine the intended enrollment choice, retroactive enrollments will not be processed for multiple transactions that reject because the enrollment requests have the same application date.” (p.133, MA Manual)