The top reported proficiency rate is 30% in Science. The lowest is 23% in Math.
Original Research by School Decision on Cortland Elementary School
Cortland Elementary serves kindergarten through fifth grade in a small, primarily residential incorporated town in rural DeKalb County, Illinois, positioned immediately east of DeKalb and just south of Sycamore. The school enrolls a diverse student body in a growing community characterized by new single-family subdivisions and a suburban-rural setting. The enrollment is typical for an elementary school of its grade band, with a young demographic profile across the grades served.
The student population is notably diverse by race and ethnicity. Hispanic students make up a substantial portion of enrollment, followed by white students. Black students and multiracial students comprise smaller shares. Data on free or reduced-price lunch eligibility and English learner status were not provided, so a parent may want to check with the school directly on the share of students qualifying for lunch programs or receiving language support.
Cortland Elementary's state test results show consistent underperformance in both English language arts and mathematics across the tested grades. In third-grade English language arts, about a quarter of students scored at proficiency levels 3 or 4 on the Illinois Assessment of Readiness, with similar results across fourth and fifth grades, though fifth-grade performance edges higher. In mathematics, proficiency rates across third, fourth, and fifth grades cluster in the low-to-mid twenties. Fifth-grade science results, the only science grade tested at the elementary level, show proficiency at similarly low levels. These results place the school in the bottom quartile of overall proficiency when compared against other districts in DeKalb County. Participation rates in testing are very high across all assessments, so these low proficiency figures reflect actual student performance rather than testing absences.
The locale itself is a close-knit town with civic anchors clustered near its center, including the Cortland Community Library and Town Hall along Somonauk Road. The town has been growing through new residential construction and is positioned as a bedroom community relative to nearby employment centers. Housing values in the area are moderate compared to state and national benchmarks. Families should be aware that the parent district, DeKalb CUSD 428, is navigating a property-tax increase in 2026 to cover health-insurance premium increases and a loss of state transportation reimbursement, a direct cost-of-living factor. The district also pursued a sales-tax referendum in November 2024 intended to lower property taxes, but it failed at the ballot, so that promised relief did not materialize. The district is concurrently implementing a facility and grade-structure reconfiguration plan called Vision For28 that will affect how students progress through buildings and classrooms over the coming years.
Cortland Elementary appears positioned for families seeking a small-town residential setting with an accessible, walkable civic core and a diverse peer environment, though the academic proficiency data indicates a school where students are currently achieving below county norms in tested subjects. A parent may want to explore with the school what instructional approaches are in place to address these gaps and what support services are available for students not yet meeting proficiency benchmarks.
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