There are 4 subspecies currently recognized (Clements et al. 2010):
T. v. velia - As described above as having black crown, back and tail with purplish-blue breast, face, and flight feather margins. Has straw-yellow opalescent rump and chestnut lower belly and undertail coverts (Restall et al. 2007). Ranges from the Guianas to the north bank of the Amazon River in Brazil (Storer 1970).
T. v. iridina - Very similar to T. v. velia but has deeper purplish blue head, flight feather margins and lower rump (Hellmayr 1936, Restall et al. 2007). Ranges from southeastern Colombia (east of Eastern Andes), southern Venezuela, eastern Ecuador, eastern Peru, northern Bolivia, and northwestern Brazil (Storer 1970).
T. v. signata - Very similar to T. v. velia except for presence of greenish silver feathers on forecrown. Inhabits northeastern Brazil, south of the Amazon, in Para (Storer 1970).
T. v. cyanomeleana - The most differentiated plumage coloration from other subspecies. Breast is bright bluish gray (instead of bluish purple) and a has greenish silver, opalescent forecrown band similar to that of signata (Hellmayr 1936, Pinto de Assis et al. 2008 ). Allopatrically distributed from the other three subspecies; inhabits southeastern Brazil from Rio de Janiero to Pernambuco (Storer 1970).
The Opal-rumped Tanager is classified in the genus Tangara, the largest genus of Neotropical birds. Tangara is divided into 13 species groups based on vocalizations, diet, geographic distributions, behavior, and appearance (Isler and Isler 1987). Isler and Isler (1987) placed T. velia in species group 13 with Tangara callophrys (Opal-crowned Tanager). These two species were formally classified together in a separate genus (Tangarella). Phylogenetic analysis of DNA sequence data confirms that these two species are sister taxa (Burns and Naoki 2004, Sedano and Burns 2010). In addition, these genetic studies showed that Tangara chilensis (Paradise Tanager), previously considered a member of species group 3, is closely related to the T. callophyrs/T. velia clade.
Due to its allopatric distribution and distinctive plumage, one of the subspecies of Tangara velia, cyanomelaena, may represent a distinct species (Ridgely and Tudor 1989, Pinto de Assis et al. 2008). In Pinto de Assis et al. (2008), comparative studies of morphological measurements and plumage color concluded that cyanomelaena should be treated as a separate species based on its diagnosability, unique plumage, and geographic isolation. No genetic data have addressed the specific status of this taxon. Although Sedano and Burns (2010) included two individuals of T. velia in their study, these were both from Amazonian populations and were shown to be less than 1% different in mtDNA sequence.