| SCHOOL | CITY | CHARTER |
| BELFAST AREA HS | BELFAST | 01/09/1989 |
| BIDDEFORD HS | BIDDEFORD | 11/20/1948 |
| BONNY EAGLE HS | STANDISH | 01/07/1963 |
| BRUNSWICK HS | BRUNSWICK | 10/12/1964 |
| BUCKSPORT HS | BUCKSPORT | 09/27/1990 |
| CAMDEN HILLS REGIONAL HS | ROCKPORT | 08/09/1995 |
| DEERING HS | PORTLAND | 01/07/1929 |
| DEXTER REGIONAL HS | DEXTER | 12/01/1931 |
| GORHAM HS | GORHAM | 11/29/1962 |
| ISLESBORO CENTRAL SCHOOL | ISLESBORO | 09/20/1988 |
| KENNEBUNK HS | KENNEBUNK | 12/12/2017 |
| LAKE REGION HS | NAPLES | 01/16/1984 |
| LEWISTON HS | LEWISTON | 01/19/1981 |
| LIVERMORE FALLS HS | LIVERMORE FALLS | 02/10/1949 |
| MORSE HS | BATH | 11/10/1952 |
| MOUNT DESERT ISLAND HS | MOUNT DESERT | 10/30/1944 |
| MOUNTAIN VALLEY HS | RUMFORD | 11/15/1963 |
| NORTH YARMOUTH ACADEMY | YARMOUTH | 11/13/1962 |
| ORONO HS | ORONO | 07/02/1985 |
| PORTLAND HS | PORTLAND | 02/12/1968 |
| PRESQUE ISLE HS | PRESQUE ISLE | 05/31/2017 |
| ROCKLAND HS | ROCKLAND | 11/22/1948 |
| SANFORD HS | SANFORD | 10/25/1993 |
| SOUTH PORTLAND HS | SOUTH PORTLAND | 04/04/1927 |
| THORNTON ACADEMY | SACO | 11/26/2007 |
| VAN BUREN DISTRICT HIGH | VAN BUREN | 11/26/1979 |
| VINALHAVEN HS | VINALHAVEN | 10/04/1999 |
| WATERVILLE HS | WATERVILLE | 10/29/1985 |
| YORK HS | YORK | 04/20/1987 |
