Sheffer was first seen on a nationwide basis as Ian Hayden on the ABC daytime soap opera One Life to Live, and on the 1983 prime time serial The Hamptons. His earliest starring assignment in films was as the best friend of troubled teenager Emilio Estevez in That Was Then... This Is Now (1985), a reformatory camp inmate in Fire with Fire (1986), an antagonistic rich kid in Some Kind of Wonderful (1987), and the romantic love interest of an overweight cosmetician in Baby Cakes (1989).