In January 1963, Republic Act No. 3705 transformed the Ilocos Norte Normal School into Northern Luzon Teachers College (NLTC). By 1977, NLTC introduced a four-year education program. Recognizing the need for practical training, the Bureau of Public Schools established the NLTC Laboratory High School in 1974-1975. In 1976, NLTC was renamed Northern Luzon State University (NLSU), and the high school became NLSC Laboratory School.

In 1978, NLTC transitioned to the College of Education at Mariano Marcos State University (MMSU) under P.D. 1279, leading to the renaming of the high school as University High School Laoag. In 1986, Executive Order 86-02 merged various University High Schools in the region, but this was later repealed by the General Appropriation Act of 1999, which reduced enrollment numbers.

In 2007, MMSU aimed to boost high school enrollment to 500 students across four years, with three sections of at least 30 students each. Today, the high school functions as a laboratory for student teachers in the BSED program at MMSU's College of Teacher Education, maintaining its status as a center of excellence in secondary education in Ilocos Norte and Laoag City, excelling in both academics and extracurricular activities.