Andy and Margaret have served for more that 25 years as disciple makers and church planters in Tanzania, East Africa. Andy is the Unit Leader for AIM's missionaries in western Tanzania.

Their current assignment began in 2015 to the region of Tabora, to work among the Nyamwezi people, who largely have remained in the stronghold of Islam. The Nyamwezi are the second largest tribe in Tanzania. They embrace Islam, African traditional beliefs, and Christianity. They have much respect for their ancestors, "the living dead", to whom they offer sacrifices and rely on for benevolences. Most claim to be Muslims and follow the five pillars of Islam.

Working under the Africa Inland Church, the Andersen's vision is to teach Biblical principles, start churches, and train and equip church leaders and new believers. Much of their ministry is in the context of building relationships with their neighbors and addressing the needs of the community, sharing Jesus through word and deed.

Activities include conservation agriculture, clean water procurement, religious education in public school, equipping local churches through theological education, discipleship, and a Bible and Literature project.

Evangelism methods include showing the Jesus Film, orally communicating Bible stories chronologically, preaching, initiating discovery Bible studies, and Community Bible Study.  Additional ministries among the Nyamwezi include health ministries and Bible translation.

Andy was born and raised in Kenya. From 1997-2015, the Andersens planted multiple churches on the islands of Lake Victoria and started an elementary school, Lake Victoria Christian. They have three children who were raised on the mission field. Abigail and Ben are both enrolled in the Torrey Honors program at Biola University in California. Abigial is studying nursing and Ben is studying psychology. Caleb attends high school at AIM's Rift Valley Academy in Kenya.