What happens if a beneficiary enrolled in a MA-only HMO also signs up for a PDP plan?

When a beneficiary who is enrolled in a Medicare Advantage (MA) plan, specifically an MA-only Health Maintenance Organization (HMO), simultaneously enrolls in a standalone Prescription Drug Plan (PDP), it results in a significant automatic change to their coverage. The Medicare Advantage plan that the beneficiary is enrolled in already provides all the basic services covered by Original Medicare, including prescription drug coverage, if it is an MA-PD plan.

If the beneficiary enrolls in a separate PDP while still being enrolled in an MA-only HMO, Medicare regulations state that the individual will be automatically disenrolled from their MA plan. This is because having both an MA plan (with an integrated prescription drug benefit) and a standalone PDP creates a conflict in coverage, violating the rules that govern Medicare enrollment.

This rule ensures that beneficiaries are not simultaneously enrolled in plans that provide overlapping services, which could lead to confusion about coverage and potential gaps in care. Therefore, the consequence of enrolling in a PDP while being in an MA-only HMO is the automatic disenrollment from the MA plan.