You can choose to make Original Medicare your primary health insurance, even if you plan to continue working. If Medicare has better benefits than the plan offered by your employer, it is worth it to consider making Medicare your primary insurance. You will want to, however, make sure you choose one or the other. You do NOT want to enroll in Medicare Part B while remaining on your employer's health insurance. You will need to decide to either remain on the group plan, or transition into Medicare completely with either a Medicare Supplement/ Medigap plan, or a Medicare Advantage plan. You can, however, remain on your employer plan and enroll in Medicare Part A.