Three out of 10 Americans - or 15.7 million people - who are on Medicare have chosen to leave Original Medicare and enroll in a privately-managed Medicare Advantage plan. A large percentage of these well-intentioned seniors enrolled in such a plan without being told or understanding that leaving Original Medicare to enroll in a Medicare Advantage plan could have a negative impact on their access to health care and financial well-being the rest of their lives. Even worse, many were never told that changing from Original Medicare combined with a Medicare Supplement for a Medicare Advantage plan could be irreversible after a short period of time. This new book from Medicare expert and author of "Medicare is not one-size-fits-all" Charles Bradshaw explains in detail how Medicare Advantage plans may save a little money when someone is younger and healthier but can limit access to health care and cost a lot more in later years when health issues may develop.