Updated 3/16/2026 | Written by Ken Connolly Key Points: Original Medicare is robust, but has a few grey areas that could lead to surprise bills Part A & B have grey areas with Cataracts, Vitamin Deficiency Tests, Cruise Ships and Chiropractic Services Part D has grey areas with weight loss medications and erectile dysfunction medications What are some surprise bills and costs you could have while on Medicare? What are some things that are covered by Medicare but not in every