Alcantara comprises 9 barangays with an estimated population of 12,070. 4 of its barangays (44%) are connectivity dead zones with no recorded cell tower from either the national registry or crowdsourced data.
| Barangay | Population | Towers | Coverage |
|---|---|---|---|
| Cabadiangan | 629 | 0 | Dead zone: no towers from any source |
| Cabil-isan | 627 | 0 | Dead zone: no towers from any source |
| Candabong | 1,011 | 1 | Crowdsourced signal only (no registered tower) |
| Lawaan | 1,736 | 2 | Crowdsourced signal only (no registered tower) |
| Manga | 716 | 0 | Dead zone: no towers from any source |
| Palanas | 2,657 | 3 | Crowdsourced signal only (no registered tower) |
| Poblacion | 3,745 | 4 | Crowdsourced signal only (no registered tower) |
| Polo | 479 | 2 | Crowdsourced signal only (no registered tower) |
| Salagmaya | 470 | 0 | Dead zone: no towers from any source |