The Silvery Tanager occurs in the Andes of Ecuador, Peru and Bolivia (Isler and Isler 1987, Hennessey et al. 2003, Restall et al. 2007) on both the west and east slopes (Isler and Isler 1987, Ridgely and Tudor 1989, Restall et al. 2007, Schulenberg et al. 2007). This species has been found at elevations as low as 800 m to as high as 3050 m, but usually occurs from 1500 to 2500 m (Parker et al. 1996, Schulenberg et al. 2007, Restall et al. 2007). In southern Ecuador, the species occurs in the provinces of El Oro, Loja and Azuay. In Peru, south on the west slope to Lambayeque and southern Cajamarca and on the east slope from the Amazonas to Puno (Ridgely and Tudor 1989). In Bolivia the Silvery Tanager is known only from western La Paz, Bolivia (Hennessey et al. 2003, Ridgely and Tudor 2009).
The species that are closely related to the Silvery Tanager (Sira Tanager T. phillipsi, Green-throated Tanager T. argyrofenges, and Black-capped Tanager T. heinei) primarily are allopatric, although there is sympatry between viridicollis and argyrofenges in northern Peru. Otherwise, a single subadult viridicollis was netted with T. phillipsi in Cerros del Sira in Peru, but this bird was a possible wanderer (Graves and Weske 1987).