Seneca Middle School, Holbrook NY

Original Research by School Decision on Seneca Middle School

Seneca Middle School is a regular public middle school serving grades six through eight in Holbrook, located in the Sachem Central School District on Long Island's central Suffolk County. The school enrollment is substantial for its grade band, spread across three grades in roughly balanced cohorts.

The student body is predominantly white, with a smaller but meaningful share identifying as Hispanic, Asian, Black, or multiracial. About a quarter of students qualify for free or reduced-price lunch, reflecting moderate economic diversity within the school community.

State test results reveal uneven performance across subjects and grades. In math, seventh grade stands out with proficiency near seven in ten students, while sixth grade sits just above half and eighth grade falls closer to half. English language arts results are weaker, ranging from the upper twenties in sixth grade to the low forties in seventh grade, with eighth grade in between. Eighth grade science proficiency sits at the halfway mark. When aggregated across all tested subjects and grades, Seneca's overall proficiency index positions it above the midpoint among the districts in Suffolk County, a meaningful position given the breadth of testing across the region. That said, the variation between math and ELA performance, and the notably lower results in the early grades for reading, merit attention from families interested in the school's instructional approach in literacy.

The school sits within Sachem Central School District, which has faced genuine financial headwinds in recent years. The district's proposed 2024-25 budget was rejected by voters because it would have exceeded the state tax cap, forcing a second vote and triggering cuts to middle school sports, junior varsity athletics, and secondary clubs. For 2025-26, the district managed to preserve most programs by relying on reserve funds while confronting a structural budget gap. In May 2025, voters defeated a proposition that would have sharply reduced bus eligibility, keeping the existing transportation network in place. These recurring budget pressures and referendum votes are the backdrop for families considering the district; a parent may want to look into the district's current financial trajectory and how it may shape programs and services over the next few years.

Holbrook itself is an established, car-dependent suburban hamlet straddling two towns on central Long Island. It has no walkable downtown center; commercial activity spreads along highway corridors, and the former LIRR station closed, making most residents commuters by car. The community is anchored by the Sachem Public Library and several recreational parks. Housing values in the zip code have risen modestly and are positioned above state benchmarks, reflecting Long Island's broader market. The area is undergoing infill redevelopment rather than major expansion, including conversion of the Sun Vet Mall into an open-air shopping center and new luxury rental townhouse communities. The landscape reads as a sprawling, family-oriented suburb where most households own two cars and manage school transportation independently or rely on district buses.

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Academic performance

How students perform on state tests, by grade, set against the district.

New York Regents Exams

2 courses reported · 2024-25

End-of-course exams required for a New York Regents diploma. Each row shows the cohort size and the share of students scoring at the proficient level or higher.

Course	Students tested	% proficient
Math	122	100.0%
Science	105	100.0%

Math

Grade 651%

School 51% · District 48% · ▲ 4 pts above district

▲ 6 pts above state median · ▲ 5 pts above county median

Grade 769%

School 69% · District 66% · ▲ 3 pts above district

▲ 16 pts above state median · ▲ 9 pts above county median

Grade 846%

School 46% · District 47% · ▼ 1 pts below district

▲ 9 pts above state median · ▲ 22 pts above county median

English language arts

Grade 628%

School 28% · District 35% · ▼ 7 pts below district

▼ 17 pts below state median · ▼ 17 pts below county median

Grade 741%

School 41% · District 41%

▼ 7 pts below state median · ▼ 5 pts below county median

Grade 839%

School 39% · District 45% · ▼ 6 pts below district

▼ 9 pts below state median · ▼ 5 pts below county median

Science

Grade 850%

School 50% · District 46% · ▲ 4 pts above district

▲ 17 pts above state median · ▲ 23 pts above county median

Social studies

Grade 892%

School 92% · district not reported

▲ 14 pts above state median · ▲ 1 pts above county median

This schoolSACHEM CENTRAL SCHOOL DISTRICT, same grade

Graduation rate (ACGR) reflects the federally published Adjusted Cohort Graduation Rate for the most recent year available. We refresh this data annually at the close of each academic year in June. The federal source publishes a banded rate (for example, "90-94%") instead of an exact number for cohorts small enough to risk identifying individual students. The state distribution chart, where shown, plots every school in the state with a published rate or band; schools whose rate is federally suppressed are excluded. Where the federal source publishes a band rather than an exact rate, the school is placed within its band using a stable, ID-derived offset, so its position is consistent across visits.

Proficiency by household income

English language arts

Grade 6Lower-income24%Higher-income32%8 pp gap

Grade 7Lower-income19%Higher-income51%32 pp gap

Grade 8Lower-income30%Higher-income45%15 pp gap

Mathematics

Grade 6Lower-income32%Higher-income64%32 pp gap

Grade 7Lower-income48%Higher-income80%32 pp gap

Grade 8Lower-income53%Higher-income36%17 pp gap