Definition
ACGR stands for adjusted cohort graduation rate. The four-year measure is the percentage of an adjusted ninth-grade cohort that earns a regular high-school diploma within four years. The NCES graduation-rate technical notes explain the cohort rules.
What is adjusted?
The cohort accounts for documented transfers and other permitted changes over the reporting period. Its size is not the school’s total enrollment. For example, 180 graduates in an adjusted cohort of 200 gives 90%; dividing by all students in grades 9–12 would answer a different question.
Exact, estimated, and unavailable rates
K12 Atlas combines state and EDFacts coverage and preserves estimate flags. Do not treat an estimated or rounded percentage as an exact graduate count. An unavailable rate can reflect school type, missing coverage, or protected reporting; it is not a zero graduation rate.
Comparing rates
Keep the cohort year and completion window visible. Use compatible cohort counts when aggregating; an average of school percentages is not an official state rate. The graduation-rate guide explains this distinction, and the release coverage summary separates exact values from wider coverage.