From 2009 to 2012 Amtsberg was a member of the State Parliament of Schleswig-Holstein, where she served as her parliamentary group's spokesperson on refugees and Neo-Nazism.

In 2017, she ran again on list position 1 and as a direct candidate in the constituency of Kiel 5 and was re-elected.

In addition to her committee assignments, Amtsberg has been part of the German delegation to the Parliamentary Assembly of the Council of Europe since 2014.

She has served as deputy chairwoman of the German-Turkish Parliamentary Friendship Group (since 2018) and 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, Iraq, Yemen, Jordan, Qatar, Kuwait, Lebanon, Oman, Saudi Arabia, Syria, United Arab Emirates, and the Palestinian territories (2013–2017).

[6] Under the umbrella of the German Parliaments' godparenthood program for human rights activists, Amtsberg has been raising awareness for the work of persecuted dissidents Narges Mohammadi of Iran, Günal Kurşun of Turkey, and Issa Amro of Palestine.