Best Public Schools in Zip Code 06378

Zip code 06378 in Stonington, Connecticut contains exactly one school: Deans Mill School, an elementary school serving grades PK–5 under the Stonington School District.

Deans Mill School is a high-performing elementary school, consistently exceeding district and state averages in both English Language Arts and mathematics. In the 2025–2026 school year, 4th-grade math proficiency reached 78.4%, roughly 26 points above the state average, while 3rd-grade math hit 75.4% compared to the state’s 52.2%. The school also stands out for its exceptionally low chronic absenteeism rate of just 4.8%, far below the district’s 13.4% and the state’s 16.4%. With a favorable 11:1 student-teacher ratio and only 12.59% of students eligible for free or reduced-price lunch, the school benefits from a supportive, relatively affluent community. It serves 429 students and spends about $18,105 per pupil.

While Deans Mill remains a top-tier school, its statewide ranking has slipped over the past few years, from 43rd (91st percentile) in 2023–2024 to 97th (80th percentile) in 2025–2026. Year-over-year, ELA proficiency across grades 3–5 dipped from roughly 77.5% to 72.3%, and 5th-grade science fell from 73.7% to 64.0%, though math stayed nearly flat at about 75%. Even with these shifts, the school outperforms its own district in nearly every tested subject and grade—the only exception being 5th-grade science, where both are exactly even at 64%. Families in zip code 06378 should note that because no middle or high schools exist in the zip code, students will need to attend schools elsewhere in the district after 5th grade.