My Mom has supplemental (Part B) Plan A, which is the cheapest payment. She can afford a more expensive plan, but I'm unsure which I should choose. She is 87 years old and is in fairly good health. High blood pressure and early dementia seem to be her only ailments at this time. Has anyone had bad experiences with plan A? Should I choose F or G? I am afraid of the chance of a huge medical bill in the future.