The top reported proficiency rate is 45% in English language arts. The lowest is 44% in Math.
Original Research by School Decision on Sage International School Middleton
Sage International School Middleton is a free public charter school in Boise offering an International Baccalaureate framework across its grade span. The school serves kindergarten through tenth grade in the current year, and publicly reported information indicates it has begun adding eleventh grade with plans to grow into a full K-12 campus. As an authorized IB World School, it offers the Primary Years Programme for elementary grades, the Middle Years Programme for grades six through ten, and the Diploma Programme for the upper high school grades. A family can keep a child here from kindergarten through graduation, with the opportunity to earn an IB Diploma alongside a standard Idaho high school diploma, a pathway that is uncommon among free public options in the area.
The IB authorization is the school's defining academic feature. The framework emphasizes inquiry-based learning, international-mindedness, and a structured approach to writing and research that runs through all three programmes. For parents drawn to that pedagogy, this is the central reason to consider Sage. The trade-off is that IB schools often look different from traditional public schools in how they organize instruction, and families comfortable with a more conventional sequence may want to understand how the MYP and DP requirements map to coursework they expect.
On state assessments, results are mixed. Math proficiency in third and fourth grade sits near or just above the midpoint, with fourth grade the strongest. Fifth grade math results come in well below that level, with the reported range low enough to stand out. Sixth and seventh grade math land in the middle band. English language arts shows a similar spread, with sixth grade the strongest point and fifth and eighth grade somewhat below. Science results for the tested grades fall below the midpoint. Several grade-level results are reported as ranges rather than precise figures, and some counts are suppressed, which limits how finely a parent can read year-to-year performance at those grades. The available data represents a single year, so trend direction is not established.
The school's enrollment is modest for a campus spanning kindergarten through tenth grade, which means each grade cohort is small. The student body is predominantly white, with a sizable Hispanic presence and very small representation from other racial and ethnic groups. The share of students qualifying for free or reduced-price meals is low relative to many public schools. Information on students receiving special education services and English learner support was not available in the data provided, so families whose children need those services should ask the school directly about what is in place.
Boise frames the housing and community context. The city is Idaho's capital and largest population center, with a mix of state government, technology employers such as Micron Technology, and major corporate headquarters including Albertsons and J.R. Simplot Company. Boise State University sits adjacent to downtown, and the cultural and civic core, including the Idaho State Capitol, Boise Art Museum, and the Basque Block, is concentrated there. The Boise River Greenbelt runs through the city as an extensive trail system. Outside the downtown and near-river corridors, the city is largely auto-oriented, with suburban development in the foothills and outer areas.
Housing in the school's zip code sits above the state benchmark and well above the national figure. Rent has moved up at a faster pace than home values recently. The broader Boise metro has seen sustained in-migration, and the school's own grade-span expansion reflects some of that growth pressure on the demand for public school options. A parent weighing this school should weigh the IB pathway and small-cohort environment against the mixed assessment results and the gaps in the publicly available data on special populations. Asking the school directly about how it supports students working below proficiency, and what special education and English learner services look like in practice, would help round out the picture.
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