San Isidro comprises 12 barangays with an estimated population of 9,578. 12 of its barangays (100%) are connectivity dead zones with no recorded cell tower from either the national registry or crowdsourced data.
| Barangay | Population | Towers | Coverage |
|---|---|---|---|
| Abehilan | 412 | 0 | Dead zone: no towers from any source |
| Baryong Daan | 344 | 0 | Dead zone: no towers from any source |
| Baunos | 427 | 0 | Dead zone: no towers from any source |
| Cabanugan | 1,110 | 0 | Dead zone: no towers from any source |
| Caimbang | 538 | 0 | Dead zone: no towers from any source |
| Cambansag | 615 | 0 | Dead zone: no towers from any source |
| Candungao | 1,234 | 0 | Dead zone: no towers from any source |
| Cansague Norte | 333 | 0 | Dead zone: no towers from any source |
| Cansague Sur | 456 | 0 | Dead zone: no towers from any source |
| Causwagan Sur | 848 | 0 | Dead zone: no towers from any source |
| Masonoy | 644 | 0 | Dead zone: no towers from any source |
| Poblacion | 2,617 | 0 | Dead zone: no towers from any source |