Is Medigap The Same As Part B? 
No . Part B is your Original Medicare physician insurance - it 's one of the two parts of Original Medicare , the other being Part A -LRB- hospital insurance -RRB- . You must have both Medicare Part A and Part B in force to buy a Medigap plan . Original Medicare pays for the first 80 % of healthcare expenses , leaving you responsible for the other 20 % . Depending on which Medigap plan you buy , it will cover all or a portion of the other 20 % of expenses . The idea behind adding a Medigap plan to your Original Medicare coverage is to create a very predictable healthcare expense structure and limit costs your can be responsible for . I hope the information is helpful . If you 'd like to learn more about Medigap plans and how they help you , please feel free to contact me for help . I 'm an independent insurance broker with a strong background in senior insurance products and am licensed in many states and with over 40 insurance companies . Thanks very much . 