If your current Medicare Advantage plan is not being offered next year and you do not choose another plan, you will be enrolled by default in traditional Medicare. In this case, if you do not receive extra help with your Part D costs, then you will need to select a Part D prescription drug plan (PDP) if you want Medicare drug coverage, unless you have drug coverage from another source of coverage (for example, the VA or from your former employer or union).
If you would prefer to stay enrolled in a Medicare Advantage plan, you may shop around and enroll in a new plan during the Medicare Open Enrollment period, which runs from October 15 through December 7. Note that when a plan is discontinued, you will typically qualify for a Special Enrollment Period (SEP), which gives you more time to enroll in a new plan outside of the annual Medicare Open Enrollment period. If you receive notice that your plan is not being renewed in the following year, you will have from the first day of the Medicare Open Enrollment period (October 15) through the last day in February of the following year to select a new plan or switch to traditional Medicare. You can also use the annual Medicare Advantage Open Enrollment period (January 1-March 31) to switch to a different Medicare Advantage plan or switch to traditional Medicare.