Enrolling in a Medicare Supplement plan is easy and can be done online, over the phone, or through an insurance agent. Make sure you work with an independent agent if you're looking to save money. They can shop multiple companies vs only 1 if you call the carrier direct. The first step is to have your Medicare card ready. You will need to provide some basic personal and contact information. Once you have provided this information, you will be able to choose a plan that best suits your needs. There are a variety of plans available, so it is important to compare the benefits of each before making a decision.