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Mercer Island High School

Mercer Island School District · High · grades 8-12 · 9100 SE 42nd St, Mercer Island, WA 98040-4107

Location

9100 SE 42nd St, Mercer Island, WA 98040-4107

Academic snapshot

Meeting standard, latest year
83.7%
SBAC ELA+Math combined, 2024-25
Meeting standard, 3-year
79.9%
#6 of 173 high schools region-wide · #1 of 1 in this district
Exceeding standard, latest year
57.7%
SBAC Level 4, the top score band
Exceeding standard, 3-year
55.5%
#7 of 173 high schools region-wide · #1 of 1 in this district
3-year trend

Student outcomes

Graduating in 4 years
96.2%
Of the entering 9th-grade class
Enrolled in college
68.0%
Any 2/4-year, first year after HS
9th graders on track
95.5%
Earned all attempted credits
College-level coursework
80.6%
AP / IB / Running Start / CTE
Regular attendance
77.7%
Missing fewer than 2 days/month

Directly from OSPI Report Card (graduation, postsecondary via ERDC, ninth-grade on track, dual credit, growth, attendance). Latest published year.

Who attends

Students from low-income homes
7.2%
English language learners
2.7%
Highly Capable program
14.5%
Enrollment
1,453
Kids per typical block
Density band: unknown

Teachers

Teachers (latest)
115
Avg years experience
14.9
MA-degree share
80.0%
3-year experience trend

Avg years and MA-degree share are direct OSPI publications; the 3-year trend is our derivation. From data.wa.gov/yp28-ks6d.

School pathway

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.

Competition and advanced-peer evidence

Aggregated from WHSCA, Washington Science Olympiad, The Blue Alliance, and the Seattle Times National Merit list. "Known counts" only, missing public evidence is not proof of absence.

Highly Capable / gifted pathway

Curated from district Highly Capable program pages, with observed-at dates and confidence labels.

Research dossier

Mercer Island High School

Mercer Island School District · grades 9–12 · 1,453 students · the island's sole public high school

The verdict

Most Eastside families know the shorthand for Mercer Island High School: an affluent island's single high school, a near-automatic pipeline to four-year colleges, and the stress that goes with it. All of that checks out. What the shorthand misses is the moment the school is in. Enrollment is sliding, the teaching staff has contracted about 15% in three years, and in January 2026 the district responded by opening grades 6–12 to nonresident transfers for 2026-27, capacity permitting. That makes this one of the few schools of its caliber a family can currently apply into without buying the address.

The other recalibration is what the school actually sells: breadth and open access, not selectivity. There is no cohort to test into. The Highly Capable track dissolves at the high-school door, and any student can stack Advanced Placement (AP) courses without a cap. Its genuinely state-leading results come in band, student broadcasting, DECA (a business and marketing competition club), and athletics rather than math-olympiad pipelines. The numbers that dazzle in isolation also deserve a second read. A 90.7% English proficiency rate is mid-pack among demographically similar Washington schools, and the student newspaper documents the costs of the achievement culture, from GPA anxiety to a normalized drinking scene, with unusual candor.

Researched 2026-06-27. Citations and claim ledger included in the full dossier.

That is the free excerpt. The full dossier is the rest of the file: how these outcomes hold up in context, how deep the advanced-peer group actually runs, how families get in (and who doesn't), culture signals from handbooks and climate surveys, logistics, neighborhood context, the open questions to ask on your tour, and every citation, so you can check our work. Unlock it for $9, or get a $29 Research Pass with 3 dossiers included.

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Sources

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