Gathering high school completer and dropout data and maintaining annual records provides longitudinal information on students which allows a district to observe its unique patterns of school dropouts. That information may assist schools to target prevention and intervention programs and policies that focus on local circumstances and address the problems at their roots. The information can also assist schools to meet accreditation standards for follow-up of students no longer in attendance and federal reporting requirements. The Achievement in Montana (AIM) system was fully implemented in the 2006-07 school year. It was designed as a centralized collection of student level data. The AIM system is now treated as the system of record for federal and state reporting. All students who enroll in a public school in Montana are assigned a nine-digit StateID. This StateID follows the student through his or her Montana school career. Student enrollments are tracked through this StateID, so that Office of Public Instruction personnel can report on the student's progress until graduation or completion of 12th grade. Demographic data are also associated with the StateID, including race/ethnicity, gender, birth date, and name. This StateID is used, where possible, in other statewide data collections, such as Special Education Child Count or the Migrant Program data system, as a secondary identifier. AIM is used to determine program participation for the fall enrollment period, as well as for the spring collection for criterion referenced testing. These programs include free/reduced lunch participation, special education participation, and LEP program participation. This report provides information on: (1) Purpose of Gathering High School Completer and Dropout Data; (2) Montana High School Completer and Dropout Data Glossary; (3) Collecting High School Completer Data; (4) Collecting Dropout Data; (5) Using Graduate and Dropout Data; and (6) Related Reports (Special Education Data Collection; School Discipline Data Collection; and Carl Perkins Vocational Education Concentrators).