Already as a student Bilger joined the
Young Union (JU) in 1996 and was also a member of the CDU. From 1998 to 1999 he served as chairman of the Baden-Württemberg state branch of the Pupils' Union and from 1998 to 2000 as federal managing director of the Pupils Union Germany. In 2006, Bilger was elected chairman of the Junge Union Baden-Württemberg and was confirmed in office in the years 2008, 2009 and 2010. In 2011, Bilger was elected district chairman of the CDU North Württemberg, the largest of the four CDU districts in Baden-Württemberg. He won clearly against his competitor, the former Secretary of State for Arts,
Dietrich Birk. After his election as CDU district chairman, he ran again as country chairman of the Junge Union and was replaced in this office on 12 November 2011 by the Mannheim CDU city councillor
Nikolas Löbel.
Member of the German Parliament, 2009–present In the
2009 federal election, Bilger won the direct mandate in constituency of
Ludwigsburg with 39.9% of the vote and became a member of the German Bundestag. In the 17th Bundestag he was a full member in the Committee on Transport, Construction and Urban Development, a member of the Parliamentary Advisory Council on Sustainable Development and a deputy member of the Committees Health and Environment, Nature Conservation and Nuclear Safety. He was also a full member of the Enquete Commission Growth, Prosperity, Quality of Life. In the
2013 federal election, Bilger won again with 50.4% of the vote the direct mandate in constituency of Ludwigsburg. In the 18th Bundestag, he was a full member in the Parliamentary Advisory Council on Sustainable Development, the Committee on Transport and Digital Infrastructure and in the Joint Committee. He has also been Chairman of the MIT Transport Forum since 2013 and since 2016 a full member of the Conciliation Committee of the German Bundestag and the Bundesrat. On the Committee on Transport and Digital Infrastructure, Bilger served as his parliamentary group's
rapporteur on
electric vehicles and
alternative fuel vehicles. In addition to his committee assignments, Bilger also headed the Parliamentary Advisory Board on Electromobility. Furthermore, he was also Chairman of the Young Group, the association of all Union members under the age of 35, until January 2018. In the
2017 federal election, Bilger won again the direct mandate in the constituency of Ludwigsburg with 38.3%. He became once again a full member of the Committee on Transport and Digital Infrastructure. In the associated working group of the CDU / CSU parliamentary group, he was elected at the end of January 2018 with 95.5% of the votes as chairman and deputy chairman of the group. During the coalition negotiations between the Union and the SPD, Bilger was part of the working group on transport and infrastructure, led by
Thomas Strobl,
Alexander Dobrindt and
Sören Bartol. From 2018 until 2021, he served as Parliamentary State Secretary at the Federal Ministry of Transport and Digital Infrastructure under minister
Andreas Scheuer. In this capacity, he was also the Federal Government Coordinator for Freight and Logistics. From 2021 to 2025, Bilger served as one his parliamentary group's deputy chairs, under the leadership of successive chairs
Ralph Brinkhaus (2021–2022) and
Friedrich Merz (2022–2025). In this capacity, he oversaw the group’s legislative activities on agriculture,
environmental policy, nature conservation and consumer protection. Since the
2025 elections, Bilger has been his parliamentary group's
chief whip, under the leadership of chairman
Jens Spahn. ==Other activities==