Mason performed on November 29, 2009 at the Dizzy Feet Gala in Los Angeles, California at the Kodak Theater. She and Jason Glover performed their popular contemporary piece, "If It Kills Me", choreographed by Travis Wall, and originally performed Top 10 week on SYTYCD. Glover has described Mason as "Unique. You just don’t find Dancers like her. She has beautiful lines, is funky and charismatic, and has so much life onstage. Not only does it show in her movement but also on her face. Jeanine is a brilliant performer and one of my favorite people to watch — not just in our group, but out of any Dancer I've seen, from Gregory Hines to Gene Kelly."

On November 9, 2010, Mason performed a contemporary-ballroom dance with Mark Ballas to John Legend's "Ordinary People" on the television show, Dancing With the Stars.

Mason was born in Miami, Florida, and grew up in a dance-oriented family in Pinecrest, an affluent Miami neighborhood. Both of her parents are of Cuban descent. Mason began her dance training at the age of three in ballet and flamenco, and went on to study jazz, acrobatics, hip-hop, modern, and contemporary dance. Mason began her study of theatre at age 11 with community and middle school productions. Upon moving to Los Angeles, California, Mason continues to study theater while also keeping a focus on film and Television at The Michael Woolson Studio. Jeanine graduated cum laude from UCLA in the Spring of 2014 and accredits the knowledge that she has attained at the school to fueling her creative work. "It’s always interesting to me how my studies mirror my life. Any time I’m learning new academic material, I find a way to use it in my work. And the more material I have to pull from, the richer that work becomes."

Shortly after completing So You Think You Can Dance, Mason turned her full attention to channeling her performing skills into her other lifelong love, the craft of acting. Her on-screen career began when Mason starred in the Halloween episode of Nickelodeon's hit show, Big Time Rush. From there, she appeared in The Bling Ring, CSI: Crime Scene Investigation, The Fresh Beat Band, and Hollywood Heights before landing the recurring role of Cozzette on ABC Family’s Bunheads and leading roles in Hot Mess, and Delirium. She has also booked roles on Major Crimes and Secret Life of the American Teenager as well as several smaller, independent projects. Currently, Mason has a recurring role on ABC's hit medical drama Grey's Anatomy as Dr. Sam Bello.