| Abbreviation | Definition |
|---|---|
| ACHS | Air and Correspondence High School |
| ACHS | Alexander Central High School |
| ACHS | Allen Central High School |
| ACHS | American Canyon High School |
| ACHS | Amherst County High School |
| ACHS | Anderson County High School |
| ACHS | Andover Central High School |
| ACHS | Ankeny Centennial High School |
| ACHS | Appomattox County High School |
| ACHS | Arizona Collegiate High School |
| ACHS | Arlington Collegiate High School |
| ACHS | Ashe County High School |
| ACHS | Atlantic City High School |
| ACHS | Atlantic Coast High School |
| ACHS | Atlantic Community High School |
| ACHS | Aurora Central High School |
| ACIS | Association of Colorado Independent Schools |
| ACISD | Aransas County Independent School District |
| ACISD | Archer City Independent School District |
| ACMA | Arts and Communication Magnet Academy |