The long-term ministry of the Mennonite Team Equipo Menonita del Chaco Argentino with indigenous churches is supported by Iglesia Menonita Bragado and the central region of the Iglesia Evangélica Menonita Argentina (IEMA), Pike and Sonnenberg Mennonite Churches in Ohio, and Mennonite Mission Network.

A primary focus of the ministry in the Argentine Chaco is on Scriptures in indigenous languages. This has included translation projects, oral history, Bible studies and many forms of accompaniment. International Partnership Associates Alfonsina Finger and José Oyanguren, sent by the Iglesia Menonita Bragado in central Argentina, have served in the Chaco together with indigenous leaders since 2004. They focus on the development of the Castelli Bible Institute and related education projects. A radio station at the Centro Educativo Saỹaten (Qom Knowledge Educational Center) brings spiritual input, health education, and up-to-date news to its indigenous listeners 14 hours a day. 

The former Mennonite Board of Missions began mission work with the indigenous people in the Argentine Chaco in 1943. In the 1950s, the focus shifted from planting Mennonite churches to accompanying emerging indigenous churches. Mennonite Mission Network has continued encouraging the churches in their development of leaders and their unique styles of worship and organization. In 1960, Iglesia Evangelica Unida (United Evangelical Church) was founded by 28 indigenous congregations in the Chaco.

In partnership with Mennonite Mission Network, primarily from 2004 – 2011, a large Mennonite Team included workers from the U.S., Argentina and Germany, serving as an intercultural, interdenominational, international team. In a fourteen year project, the Mennonite Team played a key coordination role with indigenous translators and the Argentine Bible Society in finishing the first complete Toba Qom Bible translation in 2014. Study guides were also prepared for the Old and New Testaments to share the insights of the Toba Qom translation team.