Whether they involve wrong-site surgeries, poor physician handwriting or prescription dose miscalculations, medical errors are rampant in America’s health care system. Following up on its landmark 1999 study,“To Err is Human,” the Institute of Medicine in 2006 found that a hospital patient is the victim of a medical error every single day he or she is hospitalized. Most errors have no consequences, but a 2008 study of 2000-2002 Medicare data by the for-profit health quality evaluation organization HealthGrades estimated that nearly 200,000 hospitalized patients died from potentially preventable medical errors each year. The issue remains in the news as Medicare and other insurers are increasingly refusing to pay for extra medical care necessitated by preventable medical errors. Updated March 2010.