If you already have Medicare Part A (hospital benefits) and Part B (outpatient benefits) and want to replace your employer retiree benefit plan with a Medicare supplement and stand-alone drug plan or a Medicare Advantage/HMO plan, you can make this change anytime during the year.
You can choose to select one of the Medicare supplement plans defined by Medicare. These plans allow you freedom of choice regarding your providers. In addition, you would also enroll onto a Medicare prescription drug plan (Part D) that most cost effectively covers your specific prescription needs.
Or, you may choose to enroll onto one of the Medicare Advantage HMO plans (Part C) in your area which cover both your medical and prescription drugs. With HMO plans, you would want to first check to see which HMO plans your medical group/physicians take as well as ensure that the prescription drugs you take are covered by that HMO plan.