Two subspecies currently recognized:
seridoensis, described as Streptoprocne biscutata seridoensis Sick 1991; type locality Serra do Bico da Arara, Seridó region, Rio Grande do Norte, Brazil
Breeding range unknown. Occurs in northeastern Brazil, in Piauí and Rio Grande do Norte, as a nonbreeding visitor, where it arrives in February and remains until October (Sick 1991).
Apparently identical in plumage to nominate biscutata, but differs in its smaller size, with no overlap in wing length (Sick 1991). Sick's sample size was small, however, and perhaps the validity of this subspecies should be reexamined in light of the seasonal variations in wing length reported by Pichorim (2010).
biscutata, described as Chaetura biscutata Sclater 1865; type locality Rio de Janeiro and Ypanema, São Paulo, Brazil
Occurs in southeastern Brazil from Minas Gerais south to Rio Grande do Sul (Sick 1997) and northeastern Argentina (Pearman et al. 2010).