Red-billed Tyrannulet has a broad latitudinal distribution, although it occurs only a narrow elevational band along the foothills of the Andes. Based on projected rates of deforestation in the Amazon Basin (including the foothills?), BirdLife International (2015) assesses the IUCN Red List conservation status of Red-billed Tyrannulet as Vulnerable.
The relative abundance of Red-billed Tyrannulet is rated as rare to uncommon (Ecuador; Ridgely and Greenfield 2001a) or uncommon (Peru; Schulenberg et al. 2010), although this species also probably often is overlooked (Ridgely and Greenfield 2001a, Fitzpatrick 2004, Schulenberg et al. 2010).