| Communes |
| Alto Bío Bío, Bío Bío |
| Antuco, Bío Bío |
| Cabrero, Bío Bío |
| Laja, Bío Bío |
| Los Ángeles, Bío Bío |
| Mulchén, Bío Bío |
| Nacimiento, Bío Bío |
| Negrete, Bío Bío |
| Quilaco, Bío Bío |
| Quilleco, Bío Bío |
| San Rosendo, Bío Bío |
| Santa Bárbara, Bío Bío |
| Tucapel, Bío Bío |
| Yumbel, Bío Bío |