Tanggamus Regency is divided into twenty administrative districts (kecamatan), tabulated below with their total areas (including the sea areas) and their populations at the 2010 Census[2] and the 2020 Census,[3] together with the official estimates as of mid 2023.

Notes: (a) includes the 3 kelurahan of Baros, Kuripan and Pasar Madang.

In the winter of 2009/2010, the regency suffered from flooding, which saw some 80 percent of the forest in Tanggamus severely damaged.

Landslides occurred in the district of Semaka and the flooding drowned several elephants including one within the protected Bukit Barisan Selatan National Park and another at the Way Kerap dam in Tanggamus.

A Tropical Forest World Heritage Site, Bukit Barisan has a total area of 3,568 km2.