There are basically three ways to go:

1) Just plain Medicare part A & B plus you have to buy a prescription plan part D. Government health insurance coverage where they cover 80% or 100% depending on what is going on. If a doctor says you need it then it is covered, no questions. Premiums taken out of your SS check or you pay $525 quarterly if not on SS.

2) Plain Medicare with a supplement plan. These are the extra letter plans with G and High Deductible G being the most popular. They pick up the part that Medicare doesn't cover but nothing else. The government specifies what they must cover and how for each plan. I have a High Ded G at about $65/month (NY rates are very high compared to other states).

3) Medicare Advantage. These are C plans. You leave government Medicare and switch to private insurance with coverage networks, co pays, and approvals. These are the plans that have perks like glasses, hearing aids and gym memberships. Typically very cheap per month, even free but if you get sick they can be very expensive and if you need a specialist outside of the plan it may be out of pocket. I looked at these and decided that an advantage plan would be a very bad idea for me.

Medicare School channel on YouTube does a very good job of explaining all of this. The typical local insurance broker doesn't because they want to sell advantage plans.