Harmon moved to L.A. in the mid-1990s to concentrate on an acting career. By coincidence, she met producer-actor David Hasselhoff on a transcontinental flight and impressed him enough to be offered the lead in the detective series spin-off "Baywatch Nights". Harmon quickly segued to ABC's short-lived drama "C-16" (1997-98), playing a rookie FBI agent. Between series, the actress found time to squeeze in her first feature role, a small part as spoiled wealthy woman in John Duigan's "Lawn Dogs" (1997). In 1998, she was tapped to essay the role of assistant district attorney Abbie Carmichael on the award-winning NBC series "Law & Order", a role she played until spring 2001. Harmon left the series in part because of her marriage to football star Jason Sehorn. In 2003, Harmon sexed up her character for the big-budget film "Agent Cody Banks," by placing big "shoulder pads" into her bra. Harmon played a sexy agent and the boss to the title character, which was played by Frankie Muniz.
She next had a supporting role in “The Deal” (2005), a corporate thriller released straight-to-video about a Wall Street investment banker (Christian Slater) who, along with his environmentalist partner (Selma Blair), gets involved with government conspiracy, illegal oil trading and the Russian mafia. Though the content was timely, critics lambasted the murky storytelling and flat acting. Harmon then returned to television with a regular role on “Inconceivable” (NBC, 2005), a primetime soap opera about the lives of doctors, lawyers and therapists who work together at a San Francisco fertility clinic. Despite a full season order by the network, “Inconceivable” was cancelled after two episodes. Meanwhile, Harmon costarred in “Fun With Dick and Jane” (2005), a remake of the 1976 film starring Jane Fonda and George Segal. In the updated version, Jim Carrey and Tea Leoni played Dick and Jane Harper, a married couple so desperate to retain their deluxe suburban home and luxury cars after Dick loses his job that they resort to armed robbery.