On June 2005, in order to decongest Amulung National High School laocated at the Barangay Anquiray, the School Principal, Marites Pasaraba Danao coordinated with the Principal of Baculud Elementary School, Mr. Paulino Antonio to allow the unused classrooms of the elementary to be utilized by some enrolled students of Amulung National High School who are residents of the nearby barangays of the elementary school.
Because both principals are advocates of the intellectual formation of learners of Amulung, they came into a legal agreement for the use of the 3 classrooms. After a Memorandum of Agreement (MOA) has been duly signed around 150 enrolled students of the Main School were transferred to the extension school that comprised of three (3) First year classes with 50 students each section. Five teachers were also also being pulled out from the main school namely: Mrs. Glorina P. Aquino, Mrs. Luneza B. Verzon, Jowers A. Verzon, all Provincial School Board (PSB) Teachers; Mrs. Annah-Liza P. Galano and Ms. Olivella B. Lim, both Nationally Funded Teachers. Ms. Olivella B. Lim being appointed as the Officer In-Charge.
In 2008, a 4-classroom building were inaugurated being donated by Federation of the Filipino-Chinese Chamber to Amulung National High School-Baculud Extension at the back portion of the lot of the elementary school.
Every year from then on, one Grade Level higher has been organized. On School Year 2016-2017, the school implemented the Senior High School with the General Academic Strand as the curricular offering.
At present, the school has already completed its Junior High School and Senior High School Grade levels with three hundred seventy (370) enrollees, twelve (12) nationally funded teaching personnel and one (1) non-teaching personnel.