Yellow-bellied Tanagers are resident in northern and western South America, east of the Andes. The most widespread subspecies, nominate xanthogastra, occurs from eastern Colombia east to Guyana, and south through eastern Ecuador, eastern Peru and western Brazil to Bolivia. Subspecies xanthogastra occurs in the lowlands and on the lower slopes of the Andes, up to 750 m in Venezuela (Hilty 2003), to at least 600 m ("probably higher") in Colombia (Hilty and Brown 1986), mostly below 1100 m in Ecuador (Ridgely and Greenfield 2001b), to 1500 m in Peru (Walker et al. 2006, Schulenberg et al. 2007), and to 1400 m in Bolivia (Hennessey et al. 2003).
Subspecies phelpsi is restricted to restricted to the tepui mountains of southern Venezuela in Bolívar and Amazonas, and in adjacent Brazil (Mount Uei-tepui), where it occurs at ca 1000-1800 m (that is, above the distribution of nominate xanthogastra).