Dumalag comprises 19 barangays with an estimated population of 30,676. 18 of its barangays (95%) are connectivity dead zones with no recorded cell tower from either the national registry or crowdsourced data.
| Barangay | Population | Towers | Coverage |
|---|---|---|---|
| Concepcion | 1,318 | 0 | Dead zone: no towers from any source |
| Consolacion | 1,816 | 0 | Dead zone: no towers from any source |
| Dolores | 2,385 | 0 | Dead zone: no towers from any source |
| Duran | 3,032 | 0 | Dead zone: no towers from any source |
| Poblacion | 3,253 | 1 | Crowdsourced signal only (no registered tower) |
| San Agustin | 1,045 | 0 | Dead zone: no towers from any source |
| San Jose | 1,146 | 0 | Dead zone: no towers from any source |
| San Martin | 353 | 0 | Dead zone: no towers from any source |
| San Miguel | 1,961 | 0 | Dead zone: no towers from any source |
| San Rafael | 1,313 | 0 | Dead zone: no towers from any source |
| San Roque | 1,838 | 0 | Dead zone: no towers from any source |
| Santa Carmen | 755 | 0 | Dead zone: no towers from any source |
| Santa Cruz | 2,371 | 0 | Dead zone: no towers from any source |
| Santa Monica | 363 | 0 | Dead zone: no towers from any source |
| Santa Rita | 612 | 0 | Dead zone: no towers from any source |
| Santa Teresa | 1,432 | 0 | Dead zone: no towers from any source |
| Santo Angel | 3,030 | 0 | Dead zone: no towers from any source |
| Santo Niño | 2,123 | 0 | Dead zone: no towers from any source |
| Santo Rosario | 530 | 0 | Dead zone: no towers from any source |