8215 SE 78th St, Mercer Island, WA 98040-5901
Avg years and MA-degree share are direct OSPI publications; the 3-year trend is our derivation. From data.wa.gov/yp28-ks6d.
Which schools connect to this one by attendance area. Your address decides the assignment, so confirm with the district before relying on it. See the full elementary to high-school pathways.
Self-contained HC cohort ('Code 33') in grades 3-5 hosted in a dedicated classroom at Lakeridge Elementary, historically branded E2 (Expedition for Excellence). At Islander Middle School the HC program focuses on Science, English, and Social Science; other content areas integrate with the general population. Designed for students roughly in the top 2% cognitive aptitude and top 10% academically.
Curated from district Highly Capable program pages, with observed-at dates and confidence labels.
Mercer Island School District · grades K–5 · 401 students · attendance-area neighborhood school and host of the district's self-contained highly capable classroom
Lakeridge is where Mercer Island concentrates its most accelerated elementary students. As of the 2025-26 school year, the district's official program pages place the self-contained "Code 33" highly capable classrooms for grades 3-5 in a dedicated room at Lakeridge. Even outside that room, 39.2% of the student body is identified highly capable, nearly four times the state rate. Add an 87.3% combined proficiency rate in English language arts and math, plus a Level 4 (advanced) rate in the 94th percentile among demographically similar Washington schools, and you get an elementary where the default pace of a general-education classroom is set by accelerated kids.
The catches are structural, not academic. Much of the enrichment that makes Lakeridge feel rich (chess, coding, filmmaking) is coordinated by the parent-teacher association (PTA) and fee-based rather than district-funded, so the full experience carries a price tag on top of Mercer Island housing. The district is also cutting: a $3 million deficit for 2025-26 forced a small reduction in force in April 2026. And you cannot choice-transfer in, because K-5 is closed to nonresident enrollment for 2026-27. For most families this school is really a real-estate decision about the south end of the island.
Researched 2026-06-10. Citations and claim ledger included in the full dossier.
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