Doctor of Medicine, University Oslo, 1976. Doctor of Philosophy, University Oslo, 1987.
Fosse is a specialist in general surgery and thoracic surgery, and is director of the Intervention Centre at the National Hospital. He was appointed Professor of Medicine (professor II, a part-time position) at the University in 1999. He is noted for his humanitarian work for NORWAC on the Gaza Strip with Mads Gilbert during the Gaza War.
They published a book together on their experiences in 2013, Eyes in Gaza.
President Norwegian Aid Committee, Oslo, since 1983. Lieutenant colonel Norwegian Army, since 1994. Member European Association Cardiothoracic Surgery, European Association Cardiovascular Surgery, Scandinavian Association Thoracic Surgery, European Association Endoscopic Surgery, Norwegian Association Cardiothoracic Surgery.
Married Carolyn Midsem, August 23, 1977. Children: Hilde Midsem, Eivind.