Sapphire-vented Puffleg is resident in the Andes. There is a single specimen, reportedly taken in 1898 in Merida, Venezuela (Schuchmann et al. 2001); this locality is very isolated from the nearest locality where this puffleg occurs regularly, in southwestern Colombia (Hilty and Brown 1986). Sapphire-vented Puffleg also occurs in the Andes of Ecuador, with most localities on the west slope, and "on the slopes above the central and interandean valleys; there are relatively few records from the actual east slope" on the Andes in Ecuador (Ridgely and Greenfield 2001a). There is an apparent gap in the distribution of Sapphire-vented Puffleg between southern Ecuador and northern Peru in Amazonas, south of the Marañón River. This species is widely distributed in Peru from central Amazonas south to Puno (Schulenberg et al. 2010), although it apparently does not occur in the well studied Cordillera Carpish in Huánuco. Sapphire-vented Puffleg is not reported (yet?) from Bolivia, however (Hennessey et al. 2003).
The elevational distribution of Sapphire-vented Puffleg in Ecuador is 2700-3700 m (but mostly below 3400 m) (Ridgely and Greenfield 2001a), and in Peru it occurs at 2400–3500 m (Schulenberg et al. 2010).