GACS is Guam’s first approved charter school and the only one on the island serving kindergarten through grade 12 without district boundaries limiting enrollment. Families from villages across Guahan join the same school community and remain in it through graduation.
“We do everything with a sense of purpose,” says Ann Santiago, CEO. “It is intentional and data-driven. We do not compromise standards or the rigor of the curriculum.”
That purpose shapes how GACS teaches and how it welcomes people, whether new students or new teachers.
One Community from Kindergarten to Graduation
Belonging is the trait Santiago hopes new families notice first. Students who return after trying other schools are the clearest evidence. Parents stay connected through regular communication with teachers, conferences, progress updates, school events, volunteer opportunities and digital portals that keep them informed year-round. Partnerships with local businesses and community programs give students real-world exposure through career fairs and service-learning.
The same culture extends to the adults who work there. A Teacher of the Year with 20 years of mainland experience joined GACS and, in her second year on Guahan, said she finds it rewarding to be part of the school’s family. Teachers value the direct access they have to students and their families and new staff are welcomed with the expectation that they will grow here and stay.
We do everything with a sense of purpose. It is very intentional and we are data driven. We do not compromise standards or the rigor of the curriculum.
GACS is a school that reflects, sets goals and refuses to become complacent. That discipline shows up in how individual students are taught. Students requiring additional academic support are placed in Direct Instruction (DI) classrooms—a structured, research-based model built on explicit teaching, skill mastery, repetition and continuous progress monitoring. One middle-school student arrived from another island without a formal educational background, reading below a fifth-grade level. After one year of DI and consistent assessment, that student was reading at a sixth-grade level.
Renaissance assessments at the start of the year, midyear and year-end show teachers exactly where each student stands in terms of progress. Grade-level teams meet to review progress and determine whether a student needs additional support, reinforcement or greater challenge.
College and Career Readiness follows the same intentional approach. Communication, professionalism and career exploration are built into the school day, supported by platforms like Wayfinder, WorkKeys, iReady, Xello, Edgenuity, Banzai and Renaissance. Through the Individualized College and Career Activity Portfolio, students document their strengths and build a plan for what comes next: college, a career or military service. A values-based curriculum develops work ethic, self-regulation, emotional awareness and responsible technology use, including AI.
Purpose shows up beyond academics as well. One student who had spent years at GACS managing social-emotional challenges and difficulty connecting with peers joined MathCounts, an island-wide mathematics competition. That year, the student gained the needed confidence to work with a competitive team.
Building a Home That Lasts
GACS receives $7,800 per pupil through the public charter appropriation, which funds every charter school in Guahan and has operated rent-free at its current location in Tiyan. As its curriculum and programs have grown, the building has not kept pace. Charter law currently restricts GACS from financing or acquiring its own facility. Santiago and her team are pursuing funding wherever possible, working toward a permanent campus with space for academics, athletics and the student activities the school has outgrown its current walls to hold.
It is a real constraint on a school that has otherwise built something families choose and choose again. Santiago often returns to a phrase that captures the standard the school holds itself to: ‘Knowledge speaks, but wisdom listens.’ It is part of why GACS stands out this year as Top Public School 2026.
