In January 1958, at age nine, she obtained her Actors Equity Card in the name Bernadette Peters to avoid ethnic stereotyping, with the stage name taken from her father's first name. She made her professional stage debut the same month in "This Is Goggle", a comedy directed by Otto Preminger that closed during out-of-town tryouts before reaching New York. She then appeared on NBC television as Anna Stieman in "A Boy Called Ciske", a Kraft Mystery Theatre production, in May 1958, and in a vignette entitled "Miracle in the Orphanage", part of "The Christmas Tree", a Hallmark Hall of Fame production, in December 1958 with fellow child actor Richard Thomas and veteran actors Jessica Tandy and Margaret Hamilton. She first appeared on the New York stage at age 10 as Tessie in the New York City Center revival of "The Most Happy Fella" (1959). In her teen years, she attended the Quintano's School for Young Professionals, a now-defunct private school that several famous people, such as Steven Tyler, attended.