In April 2010, The CW announced Michalka was cast in the main role of Marti Perkins on the cheerleading drama series Hellcats. The show premiered to September 8, 2010 to 3 million viewers. Despite a successful premiere, ratings failed to remain high with the series finale reaching a low 1.19 million viewers. In May 2011, The CW announced the show was not renewed for a second season. In 2010 and 2011 respectively, Michalka had major supporting roles in films Easy A and The Roommate. Michalka appeared in the independent drama film Crazy Kind of Love alongside Eva Longoria, Virginia Madsen and Amanda Crew. The film was released in July 2013.
In 2015, she was cast in The CW television series, iZombie, in a recurring role. In early May 2015, it was revealed that the previously untitled drama film she shot with sister, Amanda "AJ", was called Weepah Way for Now. The film was written and directed by her husband, Stephen Ringer, and shot in Laurel Canyon, California in July 2014. Michalka participated in the casting and production process in addition to acting in the film. It premiered at the Los Angeles Film Festival on June 16, 2015.
Michalka and her sister comprise the musical duo 78violet, and released their first album, Into the Rush, on August 16, 2005. In September 2006, they brought out a holiday album covering 9 tracks, along with two originals, titled Acoustic Hearts of Winter. In July 2007, their third album, Insomniatic, hit stores, featuring the American top 20 hit single, "Potential Breakup Song". The two were to release a fourth album in early 2010, but it was canceled after they left their label. They released a new single entitled "Hothouse" on July 8, 2013, with a new album expected to follow.
Michalka has played the piano since she was five and started playing the guitar at the age of 13. She started acting when she was five years old, mostly in church play productions. In 2012, Michalka began dating independent film producer, Stephen Ringer, whom she met on the set of her film, Sequoia. The couple became engaged at Big Sur, California, in July 2014. They married in a small ceremony in Portofino, Italy in early June 2015. She was raised Christian and continues to practice.