Hallstrom served on various boards, including the executive board of the Aloha Council of the Boy Scouts of America, the National Advisory Council of the Boy Scouts of America, and the President's Roundtable of Brigham Young University–Hawaii.

[5] In 2008, Hallstrom participated in a major donation of wheelchairs through Latter-day Saint Charities to His Majesty the King Bhumibol Adulyadej in honor of the 80th birthday of the Thai monarch.

[6] Hallstrom became a member of the Presidency of the Seventy in April 2009, filling a vacancy created by the call of Neil L. Andersen to the Quourm of the Twelve Apostles.

At that time in 2017, he began service as Executive Director of the church's Priesthood and Family Department (PFD).

During part of his time in the Presidency of the Seventy, Hallstrom served on the governing board of the Church Educational System (CES).