Usually collaborating with longtime writing partner Harvey Bullock, Allen co-wrote for a large number of television programs, including The Andy Griffith Show, The Flintstones, Gomer Pyle, U.S.M.C., Hogan's Heroes, and The Love Boat.
Allen and Bullock also created the TV series Rango, and wrote the screenplays for the feature films Girl Happy (starring Elvis Presley), The Man Called Flintstone (1966), and Don't Drink the Water (1969), among others.
As writer-producers, Allen and Bullock collaborated on shows such as Wait Till Your Father Gets Home, The Love Boat, and Alice.
He died in Los Angeles, California at the age of 57.
Allen and Bullock received a Random House award in 1956 and were nominated for an Emmy Award in 1976 for a children's program called Papa and Me.