Maag first became a member of the Bundestag after the 2009 German federal election.[1] She was a member of the Health Committee.[2] From 2018, she served as her parliamentary group's spokeswoman on health policy.
In addition to her committee assignments, Maag was part of the German-Egyptian Parliamentary Friendship Group, the German-Indian Parliamentary Friendship Group and the German-Russian Parliamentary Friendship Group.
In April 2021, Maag announced that she would not stand in that year's federal elections but instead resign from active politics by the end of the parliamentary term.[3]