San Isidro comprises 13 barangays with an estimated population of 28,942. 4 of its barangays (31%) are connectivity dead zones with no recorded cell tower from either the national registry or crowdsourced data.
| Barangay | Population | Towers | Coverage |
|---|---|---|---|
| Camarag | 1,182 | 1 | Crowdsourced signal only (no registered tower) |
| Cebu | 2,110 | 0 | Dead zone: no towers from any source |
| Gomez | 1,182 | 4 | Crowdsourced signal only (no registered tower) |
| Gud | 1,549 | 0 | Dead zone: no towers from any source |
| Nagbukel | 984 | 0 | Dead zone: no towers from any source |
| Patanad | 1,809 | 1 | Crowdsourced signal only (no registered tower) |
| Quezon | 3,093 | 12 | Crowdsourced signal only (no registered tower) |
| Ramos East | 1,849 | 5 | Crowdsourced signal only (no registered tower) |
| Ramos West | 2,715 | 6 | Crowdsourced signal only (no registered tower) |
| Rizal East (Pob.) | 2,196 | 3 | Crowdsourced signal only (no registered tower) |
| Rizal West (Pob.) | 3,051 | 0 | Dead zone: no towers from any source |
| Victoria | 3,199 | 2 | Crowdsourced signal only (no registered tower) |
| Villaflor | 4,023 | 1 | Crowdsourced signal only (no registered tower) |