In November 1948, after intensive study by Guatemalan authorities, a presidential decree was issued which authorized the School to operate as an experimental/laboratory school. This status granted it some freedom in developing its curriculum and employing foreign teachers to provide instruction in English. It also meant that the school would develop programs that contribute to the improvement of education in Guatemala. It has had this status since that time, with the last ministerial agreement authorized in 2016 for a twenty year period.
In 1972, the University del Valle de Guatemala was chartered and the School Association became the Foundation of the Universidad del Valle. In this new charter, the School became legally the laboratory school of the University. Both institutions function separately but the relationship between the two is mutually supportive with the end goal of positively impacting education in Guatemala.