San Isidro comprises 14 barangays with an estimated population of 26,224. 11 of its barangays (79%) are connectivity dead zones with no recorded cell tower from either the national registry or crowdsourced data.
| Barangay | Population | Towers | Coverage |
|---|---|---|---|
| Alegria | 1,972 | 0 | Dead zone: no towers from any source |
| Balite | 2,138 | 0 | Dead zone: no towers from any source |
| Buenavista | 525 | 1 | Crowdsourced signal only (no registered tower) |
| Caglanipao | 1,237 | 0 | Dead zone: no towers from any source |
| Happy Valley | 878 | 0 | Dead zone: no towers from any source |
| Mabuhay | 972 | 0 | Dead zone: no towers from any source |
| Palanit | 3,484 | 5 | Crowdsourced signal only (no registered tower) |
| Poblacion Norte | 2,630 | 0 | Dead zone: no towers from any source |
| Poblacion Sur | 1,042 | 0 | Dead zone: no towers from any source |
| Salvacion | 2,208 | 0 | Dead zone: no towers from any source |
| San Juan | 2,693 | 0 | Dead zone: no towers from any source |
| San Roque | 1,707 | 3 | Crowdsourced signal only (no registered tower) |
| Seven Hills | 1,520 | 0 | Dead zone: no towers from any source |
| Veriato | 3,218 | 0 | Dead zone: no towers from any source |