Hillcrest served as the high school department of Lutheran Brethren Schools from its founding until 2003, when it was incorporated as a separate school directly under the Church of the Lutheran Brethren, with its own president and school board. HLA continued to share the campus with Lutheran Brethren Seminary, the theological training institute of the Church of the Lutheran Brethren. That was until in 2015, the seminary building was given to Hillcrest, which was renovated to the new Student Union, and the seminary moved across the street to a new addition attached to The Church of the Lutheran Brethren synod offices.