PK–05 is the single most common grade span in our 98,950-school directory, but it represents only 17.1% of records. The broader lesson is more interesting: American public schools are organized in many configurations, and a familiar label such as “middle school” does not identify the exact transition years.
118
distinct reported grade spans
7,247
PK–8 or K–8 schools
3,802
PK–12 or K–12 schools
Federal directory records store the lowest and highest grade offered. We display those endpoints as a span: “PK” means prekindergarten, “KG” means kindergarten, and “01” through “12” are numbered grades. A PK–05 school therefore reports prekindergarten through fifth grade.
The 15 most common grade spans
| Reported span | Schools | Share of directory |
|---|---|---|
| PK–05 | 16,958 | 17.1% |
| 09–12 | 16,406 | 16.6% |
| 06–08 | 10,785 | 10.9% |
| KG–05 | 9,685 | 9.8% |
| PK–06 | 4,285 | 4.3% |
| PK–08 | 3,724 | 3.8% |
| KG–06 | 3,554 | 3.6% |
| KG–08 | 3,523 | 3.6% |
| 07–12 | 2,653 | 2.7% |
| 06–12 | 2,591 | 2.6% |
| KG–12 | 2,378 | 2.4% |
| PK–04 | 2,081 | 2.1% |
| 07–08 | 1,903 | 1.9% |
| PK–PK | 1,626 | 1.6% |
| 05–08 | 1,608 | 1.6% |
No single configuration dominates. PK–05 and KG–05 differ only in whether prekindergarten is reported, but each is a separate span. Six-through-eight and seven-through-eight schools create different transition points. Combined campuses such as PK–08, KG–08, 06–12, and PK–12 make a four-category elementary/middle/high vocabulary incomplete.
Broad school levels simplify the directory
For national browsing and peer comparisons, this site maps exact spans into four broad levels. That makes 118 configurations navigable, but the original grade span remains the more precise fact.
| Broad level | Schools | Share | How to read it |
|---|---|---|---|
| Elementary | 51,910 | 52.5% | Primarily elementary grades |
| Middle | 16,098 | 16.3% | Primarily middle grades |
| High | 23,638 | 23.9% | Primarily high grades |
| Other | 7,304 | 7.4% | Combined or nonstandard configuration |
“Other” is not a statement about quality or mission. It is a guardrail against forcing a combined or unusual span into a misleading conventional category. A PK–12 campus and a stand-alone prekindergarten can both require special handling even though their operations are very different.
A grade span is not always a building map
The endpoints tell you which grades the school reports serving; they do not guarantee that every grade operates at one physical site, that every student follows the same pathway, or that all grades share schedules and leadership. Districts can use annexes, shared campuses, separate academies, or program-specific arrangements.
The span can also change between school years. A growing school may add one grade at a time, while a reconfiguration may move sixth grade into or out of a middle school. That is why a current district enrollment page matters when a family is planning several years ahead.
Why grade span matters for comparisons
School size, staffing, programs, and student experience all interact with the grades served. A 600-student PK–08 school spreads enrollment across as many as ten grade levels; a 600-student 06–08 school spreads it across three. The same total can imply very different grade cohorts, schedules, and numbers of course sections.
Combined schools can also make seemingly simple comparisons unfair:
- Enrollment: compare both total size and approximate students per grade.
- Student–teacher ratio: consider whether elementary classrooms and secondary subject teachers coexist in one record.
- Programs: an AP flag on a PK–12 profile is relevant to its high-school grades, not its elementary students.
- Transitions: staying on one campus may reduce a building change, but students may still move into a distinct secondary program.
- Peer groups: a K–8 school is usually better compared with other K–8 schools than with every elementary school in the state.
A practical family check
Start with the profile’s exact span, then verify four questions on the current school or district site: Which grades will operate next year? Are all of them on the same campus? Which addresses or programs feed into the school? Where do students usually go after the final grade? For prekindergarten, also confirm eligibility and whether the program is full-day, because the directory flag alone cannot answer those questions.
Analysis notes
Counts use all 98,950 schools in our current directory snapshot. Each school counts once. Distinct spans are based on the normalized lowest-to-highest grade label published in the profile data. Broad levels are site classifications used for navigation and descriptive benchmarks; they do not replace the federal span.
Shares describe directory records, not the share of students enrolled in each configuration. A small combined school and a large comprehensive high school receive equal weight.
Sources and methodology
- NCES Common Core of Data school directory — lowest and highest grades offered.
- NCES Search for Public Schools — federal record lookup.
- US School Ratings methodology — directory processing and broad-level classification.
