Actress Meredith Baxter told the Los Angeles Times her stepfather died Tuesday after suffering a heart attack at the office of his oncologist. Manings had recently had surgery for esophageal cancer.
He and his late wife, Whitney Blake, created the comedy "One Day at a Time" for Norman Lear's production company. The show became a hit for CBS and ran from 1975 to 1984.
Manings won his Emmy Award in 1968 for his work on "Rowan & Martin's Laugh-In." The Writers Guild of America Morgan Cox Award-winner also worked on TV stalwarts such as "Leave It to Beaver," "Good Times," "McHale's Navy" and "Petticoat Junction."
Besides Baxter, Manings is survived by stepsons Richard and Brian Baxter; his sister, Muriel Manings; nine grandchildren and three great-grandchildren.