"I hadn't gone to a doctor in over 40 years! So I didn't think I needed an insurance plan to supplement Medicare when I reached age 65, since I was very healthy." 

That's what a neighbor, Mary, recently told my wife and me as she shared an unfortunate story. She had signed up for Medicare at age 65, but she hadn't bought either a Medigap plan or a Medicare Advantage plan to supplement Medicare, nor had she signed up for a prescription drug plan under Medicare Part D.

But at age 70, in spite of being in excellent health, Mary suffered a stroke. We were all surprised, given that she dances, practices yoga and tai chi, and walks regularly. She's slim, athletic, doesn't smoke and eats very healthily. She's one of the last people we thought would have a stroke, but we've since found out that strokes can strike anybody, including people who are otherwise very healthy.

Mary spent about 10 days in a hospital, followed by many days in a skilled nursing facility for rehabilitation. Now she's facing many thousands of dollars in bills for hospital, doctors, physical therapy and rehab charges because she wasn't aware of Medicare's high deductibles and co-payments.