The Highland Mammelomys is a medium-sized rat of New Guinea's upland forests. The report places it in the Central Cordillera and North Coastal Ranges.
The report describes it as a medium-sized rat weighing about 100 g.
It is reported from upland forest at 1,000–3,200 m in the Central Cordillera and North Coastal Ranges. The species was not collected during the 2005 Kaijende Highlands assessment.
An extinction-risk assessment has not been added yet.