By the time he was 17, Noseworthy was out of high school and on the stage as a chorus dancer. He toured in a road company of "Cats", before landing a gig in the original cast of "Jerome Robbins' Broadway". He made theater history when he became the last actor signed for the cast of "A Chorus Line" on Broadway. All his stage work had happened in less than three years, and by 1990, Noseworthy had relocated to Los Angeles. He appeared as the sycophantic student of music teacher Phill Lewis in "Teech", a short-lived 1991 CBS sitcom. That same year, Noseworthy made his TV-movie debut as Suzanne Somers' brother in the flashback sequences of "Keeping Secrets", the story of Somers' alcoholic, dysfunctional family. He was the bag boy whose energy enrages Anne Bancroft in "Mrs. Cage" (PBS, 1992). In 1994, Noseworthy had his best TV chance as Ed, who finds out on his 20th birthday that he is nothing more than a living experiment and will combust before his next birthday in "Dead at 21".
On the big screen, Noseworthy made his debut with a small role in "Encino Man" (1992). In 1993, he was the chain-smoking survivor of an Andes plane crash in "Alive" and in the following year was Stephen Dorff's sidekick in the disastrous "S.F.W." Noseworthy was also the grunge rock neighbor picking on Peter Brady in "The Brady Bunch Movie" (1995) and co-starred with Pamela Lee in "Barb Wire" (1996). In 1997, he twice appeared opposite Kathleen Quinlan in the thriller "Breakdown" and the futuristic "Event Horizon" and later reteamed with "Breakdown" helmer Jonathan Mostow to essay a German-speaking radio operator in the WWII action-adventure flick "U-571" (2000).