She danced on Broadway in Luis Valdez's Zoot Suit, and was resident Choreographer at INTAR under the direction of Max Ferra. She studied dance at the Merce Cunningham and Erik Hawkins Studios, and Pilates with at the Joseph Pilates original studio in NYC, which led to her 1979 teaching position at Ron Fletcher's Pilates Studio in Los Angeles. In 2007, she played the lead role Liz Estrada at the Getty Villa's commissioned update of Lysistrata. In 2015, she returned to television, appearing as a series regular in the independent TV pilot Myrna as Stefie, the ex-wife of the title character.

Carmen was born in New York City of Spanish and Cuban ancestry. She has starred in a variety of films including Night of the Juggler (1980), Comeback (1982) opposite Eric Burdon, Last Plane Out (1983), Condo (1983) Blue City (1986), Robert Redford's The Milagro Beanfield War (1988), Fright Night Part 2 (1988) as vampire Regine Dandrige, John Carpenter's In the Mouth of Madness (1995), and King of the Jungle (2000) opposite John Leguizamo. In 2012 she played a supporting role in Last Weekend and later starred in Dawn Patrol (2014).

Carmen appeared on television as the female lead in the 1992 NBC mini-series Drugs Wars: The Cocaine Cartel, as well as playing the mother of Angelina Jolie's character in the 1997 Hallmark Entertainment miniseries True Women and the female lead opposite Val Kilmer in Gore Vidal's Billy the Kid directed by Billy Graham. Julie played female lead opposite George C. Scott in two made for television movies, Finding the Way Home and Curacao (also called Deadly Waters). She was a series regular, as Linda Rodriguez Kirkridge, on the short-lived ABC sitcom Condo (1983), and guest starred in three first-season (1990) episodes of the HBO original comedy series Dream On.