 Akodon spegazzinii was first described in 1897 from Salta Province by Oldfield Thomas on the basis of a collection made in late 1896 or early 1897 by mycologist Carlos Luigi Spegazzini, after whom the species was named. Four years later, Joel Asaph Allen named Akodon tucumanensis from Tucumán Province, comparing it to various species now synonymized under Abrothrix olivaceus. Thomas named an additional species, Akodon alterus, from La Rioja Province in 1919, and considered it closely related to A. spegazzinii. A fourth species, Akodon leucolimnaeus, was described by Ángel Cabrera from Catamarca Province in 1926, but after 1932 it was associated with Akodon lactens (now Necromys lactens) as a subspecies.
