Schedeen began her career in 1974, appearing in small television roles, and was cast in a supporting part in the sci-fi horror film Embryo (1976).

[3] In New York, Schedeen first worked in summer stock theatre and commercials before signing an acting contract with Universal Pictures,[3][6] after which she moved to Los Angeles.

From 1974 to 1976, Schedeen appeared in a recurring role as Carol in the series Emergency!,[6] and guest-starred as Doctor Marcus Welby's daughter, Sandy Porter, in 12 episodes of the medical drama Marcus Welby, M.D..[7] In 1976, she was cast in a supporting part in the sci-fi horror film Embryo, co-starring with Rock Hudson and Diane Ladd, in which she played the daughter-in-law of a doctor (Hudson) who uses growth hormones to begin growing humans.

[8] In 1979, she had a supporting role in the television drama Champions: A Love Story,[9] and subsequently guest-starred on several episodes of the comedy series Three's Company from 1977 to 1982.

[7] Schedeen is best known for her role as Kate Tanner on the NBC sitcom ALF,[10] which ran from 1986 to 1990, and in which she portrayed a mother who takes an alien into her home.

[6] After the series' conclusion, she appeared in Perry Mason: The Case of the Maligned Mobster (1991), followed by supporting roles in the television film Praying Mantis (1996) and the thriller Heaven's Prisoners (1996), starring Alec Baldwin and Kelly Lynch.