On April 5, 2014, TVLine reported that Kelly McCreary best known for her series regular role on The CW's short lived medical drama Emily Owens, M.D. and recent guest appearances on Scandal had been cast in a guest star role. McCeary was slated to debut on the May 8, 2015 episode. On October 23, 2014, it was announced that McCreary was promoted to series regular after being credited as guest-starring until the eleventh episode. It was a couple of months after McCreary wrapped her stint on Scandal that she was invited to audition for Grey's. McCeary revealed that she originally auditioned for the character of "Claudette" with dummy sides, unbeknownst to her. The only information McCeary had about the character was "that she was adopted, that she would recur, and she was going to be a very important storyline." Just before the script reading for the season 10 finale, Rhimes summoned McCeary to inform her of Maggie's true identity. "I was really psyched" McCeary revealed when Rhimes informed her of Maggie's lineage. "I felt really honored to be the one to accept the challenge." However, it wasn't until McCeary experienced the reactions to Maggie's existence from her fellow cast mates that McCeary realized just how big of a deal the character would be.