Officially, it is tabbed as a sitcom. But how would you categorize it? What is the distinction between the two?
TV Dramedy
It depends on what point in the series you're talking as far as I'm concerned. The early seasons, particularly the Colonel Blake/Trapper John era were definitely the Comedy Era of the show. From the beginning of the Potter/Hunnicutt era to Radar's departure, M*A*S*H was a sitcom with dramatic overtones. Once Corporal Radar O'Riley leaves the series, until the 11th season, M*A*S*H was a dramedy. That's my opinion anyway.
"Attention all unit!"