The gray rice rat is known from the upper Marañón basin in northern Peru. Its 2016 redescription notes that the current taxon may comprise more than one species.
The dorsal fur is cinnamon-brown, and the underside is pale gray. The forefeet are whitish, and the tail is subtly bicolored above and below.
The recorded area is warm and dry, within seasonally dry tropical forest with plants such as cacti and legumes. The authors say many biological details about this species remain unknown.
An extinction-risk assessment has not been added yet.