The D'Entrecasteaux Archipelago Tree Mouse is recorded on three islands off southeastern New Guinea. Its back is reddish brown and its underside buffy white with rust-colored patches. HMW 2017 says the exact habitat is uncertain and gives several collection settings.
Its dorsal fur is reddish brown with gray bases and long black guard hairs. The underside is buffy white with patches of rust-colored hairs.
HMW 2017 says the exact habitat is uncertain. Collection records include an oak–rainforest transition and vegetation near a village. It probably lives in tropical forest across the islands, but this remains uncertain.
An extinction-risk assessment has not been added yet.