In the 2021 German federal election, Bartz stood in the Cloppenburg-Vechta constituency and was 25th place on the SPD state list in Lower Saxony. On 8 November 2022, he replaced Falko Mohrs, who took over a ministerial post in the Lower Saxony state government, in the Bundestag.[2] In parliament, he has since been serving on the Committee on Economic Affairs.[3]