Altamont Elementary, Mountain House CA

Original Research by School Decision on Altamont Elementary

Altamont Elementary serves kindergarten through eighth grade in Mountain House, a newly incorporated master-planned suburban city in San Joaquin County. The school sits in the Altamont neighborhood, one of the community's several distinct residential villages, each organized around a K-8 school and neighborhood parks. The enrollment is roughly mid-sized for its grade band, with a notably diverse student population in which Asian students make up a substantial share, followed by white, Hispanic, and biracial students. A small share of students qualify for free or reduced-price lunch, suggesting families in this area have relatively stable economic circumstances.

On California's 2024-25 state assessments, Altamont's proficiency across tested subjects and grades sits in the top quartile among San Joaquin County's school-level results. In English language arts, the school shows strength in upper elementary and middle grades, with a notable cohort of fifth-grade students performing at or above grade level. Performance in third grade ELA is weaker, and a parent may want to look into how the school supports early literacy foundations. Math proficiency is more consistent across grades, holding around the two-thirds range from fourth through eighth, with sixth grade the softer point. Science results in fifth and eighth grades cluster around the mid-60s percentile range, suggesting solid but not exceptional performance in that subject. The school has not yet released trend data, so whether these results reflect sustained performance or recent shifts is not yet clear.

The school is part of Lammersville Joint Unified School District, which serves Mountain House and surrounding areas. The district has invested in expanding capacity to meet community growth: a new K-8 school, Evelyn Costa Elementary, opened in 2023 on the southern edge of Mountain House, and Mountain House High School underwent a major classroom expansion completed in 2025 to add science labs and support additional elective and AP offerings as the community continues to grow. Those investments signal a district actively managing enrollment pressures in a rapidly developing area.

Mountain House itself is a place in transition. It was officially incorporated as a city in 2024 and is roughly halfway through its master-plan build-out. The physical setting is characteristically suburban: landscaped residential streets, new-construction homes, neighborhood parks within walking distance of schools, and tidy sidewalks designed to encourage pedestrian movement at the village scale. Most families own their homes. The walkable neighborhood design means children can access the school on foot or bike. However, the community is car-dependent for most errands and work, as public transportation is limited and many local retail and commercial amenities remain under construction or absent. Most residents commute to the Bay Area or Sacramento for work, so this is a commuter household profile. Housing costs are high relative to median household income in the region, and recent housing values have moved downward from their peak.

Parents choosing Altamont should understand they are enrolling their child in a school at the center of an active, family-oriented residential expansion where the built environment and school investments reflect growth management by both the city and district. The diverse peer environment, solid test performance relative to the county, and intentional walkable neighborhood design around the school are appealing features for families prioritizing that kind of suburban, growth-oriented setting. The school's middle grades structure (K-8 rather than a separate middle school) keeps younger teens on the same campus alongside younger children.

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Academic performance

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

Math

Grade 362%

School 62% · District 74% · ▼ 13 pts below district

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

Grade 466%

School 66% · District 73% · ▼ 6 pts below district

▲ 29 pts above state median · ▲ 40 pts above county median

Grade 567%

School 67% · District 70% · ▼ 3 pts below district

▲ 36 pts above state median · ▲ 47 pts above county median

Grade 659%

School 59% · District 73% · ▼ 14 pts below district

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

Grade 765%

School 65% · District 72% · ▼ 6 pts below district

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

Grade 865%

School 65% · District 74% · ▼ 8 pts below district

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

English language arts

Grade 352%

School 52% · District 67% · ▼ 14 pts below district

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

Grade 464%

School 64% · District 72% · ▼ 9 pts below district

▲ 21 pts above state median · ▲ 34 pts above county median

Grade 584%

School 84% · District 75% · ▲ 9 pts above district

▲ 39 pts above state median · ▲ 51 pts above county median

Grade 666%

School 66% · District 77% · ▼ 11 pts below district

▲ 22 pts above state median · ▲ 32 pts above county median

Grade 779%

School 79% · District 78% · ▲ 1 pts above district

▲ 34 pts above state median · ▲ 42 pts above county median

Grade 870%

School 70% · District 80% · ▼ 10 pts below district

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

Science

Grade 565%

School 65% · District 61% · ▲ 4 pts above district

▲ 37 pts above state median · ▲ 47 pts above county median

Grade 863%

School 63% · District 73% · ▼ 10 pts below district

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

This schoolLammersville Joint Unified, 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-income58%Higher-income67%9 pp gap

Grade 7Lower-income54%Higher-income83%29 pp gap

Grade 8Lower-income46%Higher-income73%27 pp gap

Mathematics

Grade 6Lower-income58%Higher-income60%1 pp gap

Grade 7Lower-income31%Higher-income71%40 pp gap

Grade 8Lower-income27%Higher-income70%43 pp gap