The buff-bellied climbing mouse is a rodent of montane forests in eastern Colombia, with a long tail and soft reddish-brown fur. Diet studies found mostly plant matter.
The back ranges from reddish chestnut to olive brown. Ventral hairs have gray bases and white, cream, or pale orange tips; the tail is longer than the head and body.
Stomach samples examined in Colombia consisted mostly of fruits and seeds, with most of the remainder being leaves and other plant matter; insects made up a small share.
An extinction-risk assessment has not been added yet.