Appearing as a regular on network television for so long offered the young man enviable visibility, and Koehler landed subsequent TV roles, notably in the celebrated HBO telefilm "The Positively True Adventures of the Alleged Texas Cheerleader-Murdering Mom", playing the son of the woman marked for death. He also had guest turns on the series "Full House" (ABC, 1993) and "Law & Order" (NBC, 1999) in addition to a recurring role from 1997 to 1998 in the ABC daytime drama "All My Children". In 1999, Koehler could be seen portraying the drug-snorting neo-Nazi son of brutal Aryan inmate Vern Schillinger the hard-hitting HBO prison drama "Oz".
While much of his work has been on the small screen, Koehler had racked up a handful of feature credits including supporting roles in "Heart of the Garden" (1985), "The Pick-Up Artist" (1987) and "A Kiss Before Dying" (1991). He has also won acclaim on stages in both New York and Los Angeles. In 1998 he played Ewan in the Scotland-set Off-Broadway production of Sharman Mcdonald's coming of age tale "When I Was a Girl I Used to Scream and Shout". That same year the actor took the starring role of Cripple Billy in the Los Angeles production of Martin McDonagh's "The Cripple of Inishmaan".