Good information here, especially on Medicare. I'm 60, retired but still working part-time. I collect a pension from a local government job which was exempt from Social Security. I have more than enough quarters worked from previous full time and many years of part time work paying into SS but have less than 20 years of "substantial earnings". Retirees in my situation get hit with a penalty called the Windfall Elimination Provision. For me it could be a reduction in SS payments by as much as 60%. Bipartisan legislation is introduced occasionaly to eliminate the WEP but is never seems to get out of committee.
https://www.ssa.gov/pubs/EN-05-10045...a%20government