But even after paying all of those charges, you will be far from done. Medicare pays only part of medical costs, so besides paying for their Medicare, retirees need to buy supplemental insurance policies. They are called Medigap and average about $180 a month. And you aren't done with costs after that, either. There are additional out-of-pocket expenses for medicine, dentists, eye doctors, glasses, hearing aids at $5,000 a pop and a lot more.