Deerfield Elementary School, Mountainside NJ

Original Research by School Decision on Deerfield Elementary School

Deerfield Elementary School, a regular public school serving grades three through eight, is the sole upper-elementary and middle-grade school in the Mountainside School District. Its academic profile stands well above typical levels for Union County and the state, making it a compelling option for families who prioritize strong standardized test performance in a small, suburban setting.

The school’s test results are a clear strength. In English language arts, proficiency rates across most tested grades reach or exceed roughly eight in ten students. Math performance is similarly high, with rates in the upper three-quarters to mid-eighties range across the grade levels for which data was reported. Only eighth-grade math results were suppressed, a common occurrence in small cohorts, so no public inference can be drawn there. Science, where the state’s performance criteria are set lower, is a relative soft spot, with fifth-grade proficiency around three in five students and eighth-grade proficiency around two in five. A parent may want to look into how the school supports science instruction, especially as students move into the upper grades. Overall, however, the proficiency picture is one of consistent, above-average achievement.

The student body is small and demographically homogeneous. Enrollment is concentrated in a single school that covers a wide grade span. The share of students who qualify for free or reduced-price lunch is very low. Racially, the student population is predominantly white, with smaller shares of Hispanic and Asian students, and very small shares of Black and multiracial students. Data on students with disabilities and English learners was not available in the reporting, so it is not possible to assess how the school serves those populations. The school does not receive Title I funding, which is consistent with its low share of students from low-income households.

The absence of high school grades means there is no graduation rate to report. Mountainside sends its students to Governor Livingston High School in Berkeley Heights through a sending-receiving relationship. The community texture matters here: Mountainside is a car-dependent borough of single-family homes on a ridge in northern Union County. There is no downtown. The civic nodes are Echo Lake Park, the Watchung Reservation, Borough Hall, and the two public schools, which sit in separate residential pockets. Zoning deliberately limits commercial development along the Route 22 corridor, so strip-mall sprawl is muted. Housing values in the zip code are high, well above state and national benchmarks, which reflects the school’s reputation and the area’s desirability among families who can afford entry.

In 2024, Deerfield was recognized as a National Blue Ribbon School by the U.S. Department of Education. This is a publicly reported, externally conferred distinction that signals sustained academic quality to any family evaluating the school. The district’s only other public school is Beechwood, which serves prekindergarten through second grade, meaning children spend six years at Deerfield. The class cohorts are small enough that families can expect teachers and administrators to know students individually.

The fit is for a family that wants a strong academic baseline, values a quiet suburban environment without a commercial core, and can manage the housing costs. The peer group is relatively homogenous. For a family whose child has a disability or is learning English, the missing data on special populations is a gap worth investigating directly with the school. For families who want racial or economic diversity in their child’s daily experience, Deerfield is not that match. But for families who want a public school where the typical student is performing well above state averages in math and reading, and where the setting is stable, residential, and low-stakes, this school delivers.

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Academic performance

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

Math

Grade 385%

School 85% · District 85%

▲ 35 pts above state median · ▲ 44 pts above county median

Grade 484%

School 84% · District 84%

▲ 38 pts above state median · ▲ 49 pts above county median

Grade 582%

School 82% · District 82%

▲ 39 pts above state median · ▲ 46 pts above county median

Grade 679%

School 79% · District 79%

▲ 46 pts above state median · ▲ 53 pts above county median

Grade 777%

School 77% · District 77%

▲ 43 pts above state median · ▲ 56 pts above county median

English language arts

Grade 371%

School 71% · District 71%

▲ 26 pts above state median · ▲ 30 pts above county median

Grade 483%

School 83% · District 83%

▲ 28 pts above state median · ▲ 35 pts above county median

Grade 580%

School 80% · District 80%

▲ 26 pts above state median · ▲ 31 pts above county median

Grade 690%

School 90% · District 90%

▲ 36 pts above state median · ▲ 37 pts above county median

Grade 786%

School 86% · District 86%

▲ 29 pts above state median · ▲ 31 pts above county median

Grade 881%

School 81% · District 81%

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

Science

Grade 558%

School 58% · District 58%

▲ 31 pts above state median · ▲ 38 pts above county median

Grade 843%

School 43% · District 43%

▲ 30 pts above state median · ▲ 35 pts above county median

This schoolMountainside 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.