Jefferson High School in Alexandria, Minnesota. He then went on to earn his bachelor's in business administration from the University of Minnesota in 1981.After graduation, John Hammergren worked 10 years at the American Hospital Supply, while following an MBA program from Xavier University in 1987. When American Hospital Supply was acquired, he left and joined Lyphomed. In 1991, he was hired at Kendall Healthcare Products in the midst of a LBO. Kendall Healthcare was reanimated and sold to Tyco Healthcare in 1994. In 1996, John Hammergren was hired by McKesson to run the division that sells prescription drugs to hospitals (McKesson Health Systems). In 1999, after McKesson's fraud scandal, he was named president and co-CEO of the company, and became sole CEO in 2001, and chairman of the board in 2002
Pharmaceutical ,Molecular Biology ,Clinical Research