A little background history on the MA-OEP
The MA OEP was implemented in 2019 and, as noted by CMS:
"The 21st Century Cures Act eliminates the existing MA disenrollment period [MADP] that currently takes place from January 1st through February 14th of every year and, effective for 2019, replaces it with a new Medicare Advantage open enrollment period (OEP) that will take place from January 1st through March 31st annually."
The OEP will allow 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, and return to Original Medicare Part A and Part B."
"For example, an individual enrolled in an MA-PD plan may use the MA-OEP to switch to:
(1) another MA-PD plan;
(2) an MA-only plan; or
(3) Original Medicare [Part A and Part B] with or without a [stand-alone Medicare Part D prescription drug plan] 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."
"However, this enrollment period does not allow for [Medicare] Part D [PDP] changes for individuals enrolled in Original Medicare, including those with enrollment in stand-alone PDPs."
Reminder about the timing of your enrollment or dis-enrollment during the MA OEP
When you disenroll from your Medicare Advantage plan, the dis-enrollment begins the first day of the next month after dis-enrollment.
For example, if you disenroll from your Medicare Advantage plan on February 10th, your Original Medicare Part A and Part B coverage begins on March 1st. At the same time, you can also join a stand-alone Medicare Part D prescription drug plan and your new Medicare prescription drug plan will also start on March 1st.
Reminder about your automatic SSA premium deductions
The Social Security Administration (SSA) will probably need a little time adjusting your Social Security check deductions if you decide to use the MA OEP. So if you dropped (or changed) your Medicare Advantage plan in January during the MA OEP and joined another Medicare Advantage plan or a stand-alone Medicare Part D plan (PDP), you may still see payments for your old Medicare Advantage plan deducted in February and maybe even March, then in April, any over-payments from the February and March Medicare Advantage plan premiums will be reversed and the February and March premium payments for your newly chosen Medicare Advantage or Medicare Part D plan deducted from your Social Security check.
The Medicare Advantage Plan Trial Right
If you joined a Medicare Advantage plan or Programs of All‑inclusive Care for the Elderly (PACE) when you were first eligible for Medicare Part A at age 65, and within the first year
of joining, you decide you want to switch to Original Medicare - you will have a you have a guaranteed issue right to join any Medicare Supplement that is available in your state.
Trial Right (Part II) - You have a guaranteed issue right if...
You dropped a
Medigap policy to join a Medicare Advantage Plan (or to switch to a Medicare
SELECT policy) for the first time, you have been in the Medicare Advantage plan less than a year,
and you want to switch back to your Medicare Supplement (or Medigap plan). You have the right to buy the Medigap policy you had
before you joined the Medicare Advantage Plan or Medicare SELECT policy, if the
same insurance company you had before still sells it. (If your former Medigap
policy is not available, you can buy Medigap Plan A, B, C, F, K, or L that is
sold in your state by any insurance company.)
CMS Finalizes Policy Changes and Updates for Medicare Advantage and the Prescription Drug Benefit Program for Contract Year 2019 (CMS-4182-F)
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)