The actress has revealed she will not be returning for an eighth season of the comedy, leaving Allison Janney as the sole lead.
"The past seven years on Mom have been some of the most fulfilling and rewarding of my career," Anna says in a statement obtained by Deadline. "I'm so thankful to (co-creator and producer) Chuck (Lorre), the writers, and my amazing castmates for creating a truly wonderful work experience."
"While my journey as (character) Christy has come to an end, allowing me to pursue new opportunities, I’ll be watching next season and rooting for my TV family."
"Mom" debuted on CBS in America in December, 2012.
"From the inception of Mom, Anna was the first and only choice for the role of Christy," a spokesman for the show says. "We are so proud of the stories we have been able to tell during Anna’s seven years with us. We wish Anna all the best, and we thank her for her beautiful portrayal."