In 2012, Bahr stood as a candidate for the Bundestag. She announced that she would give up her mandate in the city council after a successful election, as she sought no double mandate. Since 2013, she has been deputy chairwoman of the SPD Swabia. In 2013, she ran for the Bundestag in the constituency of Augsburg-Stadt and was elected via the list of her party. She has since been a member of the Committee on Families, Senior Citizens, Women and Youth, where she is her parliamentary group’s rapporteur on children, adolescents, and prostitution. In addition, she was a member of the Subcommittee on Citizenship and the German-American Parliamentary Friendship Group. Within the SPD parliamentary group, she belongs to the Parliamentary Left, a left-wing movement. In the 2017 federal elections, she was re-elected to the Bundestag as 4th place on the list.