In his first parliamentary term from 2013 until 2017, Hoppenstedt served as member of the Committee on Legal Affairs and Consumer Protection as well as on the Sub-Committee on European Union Law.

In addition, he was an alternate member of the Committee on Foreign Affairs and a full member of the Parliamentary Friendship Group for Relations with Arabic-Speaking States in the Middle East, which is in charge of maintaining inter-parliamentary relations with Bahrain, Irak, Yemen, Jordan, Qatar, Kuwait, Lebanon, Oman, Saudi Arabia, Syria, United Arab Emirates and the Palestinian territories.

In the negotiations to form a coalition government under the leadership of Chancellor Angela Merkel following the 2017 federal elections, Hoppenstedt was part of the working group on urban development, led by Bernd Althusmann, Kurt Gribl and Natascha Kohnen.

In the formation of Merkel's fourth cabinet, he was appointed Minister of State for Bureaucracy Reduction and Federal-State Relations at the Federal Chancellery.

[1] Amid the COVID-19 pandemic in Germany, Hoppenstedt co-chaired – alongside Silvia Breher, Tobias Hans, Yvonne Magwas and Paul Ziemiak – the CDU's first ever digital national convention in 2021.