She co-starred in films Code of Silence (1985), Some Kind of Wonderful (1987), The Dentist (1996), Election (1999), and Sully (2016), and is also known for her roles in television on Herman's Head (1991–1994), Unfabulous (2004–2007), and Walker (2021–2024).
[2] Hagan played Diana Luna alongside Chuck Norris in the 1985 action film Code of Silence.
She portrayed the young Miss Ellie Ewing in the television movie Dallas: The Early Years[2] (a prequel of the long-running soap opera Dallas), and she has appeared in several other television series, including the 1980s situation comedy The Golden Girls as Caroline, the daughter of Miles Webber, Rose's romantic partner.
At the end of the second season of Star Trek: Deep Space Nine, she played a young Vorta called Eris in "The Jem'Hadar".
She also made guest appearances in many television series, such as Charmed, Bones, Grey's Anatomy, Desperate Housewives, Ghost Whisperer, Cold Case, Private Practice, The Closer, and NYPD Blue.