Isabel comprises 24 barangays with an estimated population of 43,965. 14 of its barangays (58%) are connectivity dead zones with no recorded cell tower from either the national registry or crowdsourced data.
| Barangay | Population | Towers | Coverage |
|---|---|---|---|
| Anislag | 685 | 0 | Dead zone: no towers from any source |
| Antipolo | 375 | 0 | Dead zone: no towers from any source |
| Apale | 1,245 | 0 | Dead zone: no towers from any source |
| Bantigue | 2,129 | 0 | Dead zone: no towers from any source |
| Benog | 1,494 | 0 | Dead zone: no towers from any source |
| Bilwang | 3,047 | 2 | Crowdsourced signal only (no registered tower) |
| Can-andan | 64 | 0 | Dead zone: no towers from any source |
| Cangag | 510 | 0 | Dead zone: no towers from any source |
| Consolacion | 392 | 0 | Dead zone: no towers from any source |
| Honan | 1,020 | 0 | Dead zone: no towers from any source |
| Libertad | 10,581 | 22 | Crowdsourced signal only (no registered tower) |
| Mahayag | 2,048 | 1 | Crowdsourced signal only (no registered tower) |
| Marvel (Pob.) | 2,815 | 7 | Crowdsourced signal only (no registered tower) |
| Matlang | 5,189 | 9 | Crowdsourced signal only (no registered tower) |
| Monte Alegre | 104 | 0 | Dead zone: no towers from any source |
| Puting Bato | 1,178 | 0 | Dead zone: no towers from any source |
| San Francisco | 353 | 0 | Dead zone: no towers from any source |
| San Roque | 409 | 1 | Crowdsourced signal only (no registered tower) |
| Santa Cruz | 235 | 0 | Dead zone: no towers from any source |
| Santo Niño (Pob.) | 5,979 | 5 | Crowdsourced signal only (no registered tower) |
| Santo Rosario | 94 | 0 | Dead zone: no towers from any source |
| Tabunok | 526 | 2 | Crowdsourced signal only (no registered tower) |
| Tolingon | 1,851 | 3 | Crowdsourced signal only (no registered tower) |
| Tubod | 1,642 | 2 | Crowdsourced signal only (no registered tower) |