Tetragona Lepeletier & Serville is a genus of stingless bees with 14 recognized species occurring from Mexico to Argentina. The genus is characterized by velvety genal area, mesotibial spur present, and propodeal triangle glabrous. Within the genus, the truncata species group (T. truncata Moure and T. atahualpasp. nov.) is characterized by worker metabasitarsus with posterior angle rounded and the mandible with two short teeth of similar length. Tetragona truncata is reported with new records for Ecuador (Napo and Orellana), Peru (Huánuco, Loreto, and San Martín), and Brazil (Acre [Rio Branco] and Tocantins [Itacá, Lizarda and Palmas]). In addition, T. atahualpasp. nov. is described as a new species from regions of altitudes above 1,800 m in Colombia (Boyacá), Ecuador (Napo, Zamora-Chinchipe), and Peru (Pasco). We illustrate and discuss the identification of these two species.