Nancy Nielsen: Nielsen is president of the American Medical Association and an internist. Nielsen, who did not want her age released, has led the 162-year-old physician association since June 2008, earning praise on Capitol Hill for her approach to healthcare issues. Among her priorities are provider payment and medical liability reform as well as patient-safety improvement. She was speaker of the AMA House of Delegates from 2003 to 2007.
Top 25 Women in Healthcare