| DEPARTMENT | NAME | EXTENSION |
| Academic and Innovation Office | Jimena Jaime | 134 |
| Academic and Rector’s Office Secretariat | Mayerli Vargas | 200 |
| Administrative Office | Nicolás de Brigard | 107 |
| Admissions | Juliana Molina | 109 |
| Billing and Collections | Mónica Lobo | 231 |
| Cafeteria | 118 | |
| Communications Office | Carolina Vargas | 250 |
| Elementary School Principal | Paula Camacho | 121 |
| Extracurricular Activities | 230 | |
| School Life Office | Carolina Travecedo | 241 |
| IT Support (email, Mi GLM app, etc.) | 238, 239 and 251 | |
| Learning Support Center (KOA) | Ana María Duarte | 199 |
| Middle School Principal | César Rojas | 140 |
| Nursing | 177 | |
| Parents’ Association – ASOMONTAÑA | Diana Sanabria | 214 |
| Preschool Academic Office | Jenny Melo | 142 |
| Preschool Principal | Juana Cajiao | 143 |
| Transportation | Paola Sepúlveda | 228 |
| Upper School Principal | Olga Lucía Cabrera | 235 |
| Vice Principal of Middle and Upper School | Leopoldo García | 222 |