Isulan (Capital) comprises 17 barangays with an estimated population of 131,847. 5 of its barangays (29%) are connectivity dead zones with no recorded cell tower from either the national registry or crowdsourced data.
| Barangay | Population | Towers | Coverage |
|---|---|---|---|
| Bambad | 6,545 | 0 | Dead zone: no towers from any source |
| Bual | 11,860 | 0 | Dead zone: no towers from any source |
| D'Lotilla | 7,795 | 0 | Dead zone: no towers from any source |
| Dansuli | 2,974 | 2 | Crowdsourced signal only (no registered tower) |
| Impao | 2,560 | 1 | Crowdsourced signal only (no registered tower) |
| Kalawag I (Pob.) | 12,958 | 3 | Crowdsourced signal only (no registered tower) |
| Kalawag II (Pob.) | 19,937 | 3 | Crowdsourced signal only (no registered tower) |
| Kalawag III (Pob.) | 7,907 | 11 | Crowdsourced signal only (no registered tower) |
| Kenram | 10,986 | 10 | Crowdsourced signal only (no registered tower) |
| Kolambog | 2,256 | 1 | Crowdsourced signal only (no registered tower) |
| Kudanding | 2,387 | 0 | Dead zone: no towers from any source |
| Lagandang | 8,846 | 45 | Crowdsourced signal only (no registered tower) |
| Laguilayan | 16,138 | 4 | Crowdsourced signal only (no registered tower) |
| Mapantig | 2,701 | 2 | Crowdsourced signal only (no registered tower) |
| New Pangasinan | 1,475 | 1 | Crowdsourced signal only (no registered tower) |
| Sampao | 11,400 | 0 | Dead zone: no towers from any source |
| Tayugo | 3,122 | 2 | Crowdsourced signal only (no registered tower) |