It’s important to understand that pharmacies are not treated the same by your Medicare plan. Whether you have a standalone Part D plan (where you pay a premium each month) or a Part D component to a Medicare Advantage (Part C) plan, many Medicare members don’t realize that there are networks of pharmacies to adhere to and in some cases one drug could cost four different amounts if a member goes to four different outlets for their drugs. Many Part D plans have four different types of pharmacies—1. Preferred, 2. Non-preferred, 3. Non-network, and 4. Mail-Order.