Berg was commended for his valor while operating a dive bomber off the USS Wasp in June 1944, in which he attacked a Japanese fleet oiler in the East Philippine Sea, and ditched upon his return without suffering casualties to his crew.

Other notable film roles include the psychiatrist in Fear Strikes Out (1957) and Valerian in Alfred Hitchcock's North by Northwest (1959).

During the 1950s and 1960s, he appeared on dozens of television series, including the syndicated The Sheriff of Cochise, set in Arizona and starring John Bromfield, and Have Gun – Will Travel in the episode "The Reasonable Man".

He portrayed private detective and murderer Jason Beckmeyer in the 1957 Perry Mason episode "The Case of the Runaway Corpse."

In 1961, he was cast as Jim Gates in the episode "Frontier Week" on Joanne Dru's sitcom Guestward, Ho!, set on a dude ranch in New Mexico.