Alcantara comprises 12 barangays with an estimated population of 13,567. 8 of its barangays (67%) are connectivity dead zones with no recorded cell tower from either the national registry or crowdsourced data.
| Barangay | Population | Towers | Coverage |
|---|---|---|---|
| Bagsik | 793 | 0 | Dead zone: no towers from any source |
| Bonlao | 1,018 | 0 | Dead zone: no towers from any source |
| Calagonsao | 690 | 0 | Dead zone: no towers from any source |
| Camili | 2,423 | 0 | Dead zone: no towers from any source |
| Comod-om | 1,014 | 3 | Crowdsourced signal only (no registered tower) |
| Gui-ob | 1,768 | 0 | Dead zone: no towers from any source |
| Lawan | 236 | 4 | Crowdsourced signal only (no registered tower) |
| Madalag | 1,392 | 1 | Crowdsourced signal only (no registered tower) |
| Poblacion | 1,494 | 0 | Dead zone: no towers from any source |
| San Isidro | 290 | 0 | Dead zone: no towers from any source |
| San Roque | 920 | 0 | Dead zone: no towers from any source |
| Tugdan | 1,529 | 3 | Crowdsourced signal only (no registered tower) |