Madalag comprises 25 barangays with an estimated population of 19,099. 25 of its barangays (100%) are connectivity dead zones with no recorded cell tower from either the national registry or crowdsourced data.
| Barangay | Population | Towers | Coverage |
|---|---|---|---|
| Alaminos | 1,192 | 0 | Dead zone: no towers from any source |
| Alas-as | 663 | 0 | Dead zone: no towers from any source |
| Bacyang | 469 | 0 | Dead zone: no towers from any source |
| Balactasan | 704 | 0 | Dead zone: no towers from any source |
| Cabangahan | 418 | 0 | Dead zone: no towers from any source |
| Cabilawan | 489 | 0 | Dead zone: no towers from any source |
| Catabana | 505 | 0 | Dead zone: no towers from any source |
| Dit-Ana | 361 | 0 | Dead zone: no towers from any source |
| Galicia | 325 | 0 | Dead zone: no towers from any source |
| Guinatu-an | 363 | 0 | Dead zone: no towers from any source |
| Logohon | 459 | 0 | Dead zone: no towers from any source |
| Mamba | 787 | 0 | Dead zone: no towers from any source |
| Maria Cristina | 1,028 | 0 | Dead zone: no towers from any source |
| Medina | 1,214 | 0 | Dead zone: no towers from any source |
| Mercedes | 528 | 0 | Dead zone: no towers from any source |
| Napnot | 1,148 | 0 | Dead zone: no towers from any source |
| Pang-Itan | 497 | 0 | Dead zone: no towers from any source |
| Paningayan | 1,409 | 0 | Dead zone: no towers from any source |
| Panipiason | 1,299 | 0 | Dead zone: no towers from any source |
| Poblacion | 1,606 | 0 | Dead zone: no towers from any source |
| San Jose | 938 | 0 | Dead zone: no towers from any source |
| Singay | 607 | 0 | Dead zone: no towers from any source |
| Talangban | 591 | 0 | Dead zone: no towers from any source |
| Talimagao | 634 | 0 | Dead zone: no towers from any source |
| Tigbawan | 865 | 0 | Dead zone: no towers from any source |