San Antonio comprises 10 barangays with an estimated population of 8,252. 9 of its barangays (90%) are connectivity dead zones with no recorded cell tower from either the national registry or crowdsourced data.
| Barangay | Population | Towers | Coverage |
|---|---|---|---|
| Burabod | 908 | 0 | Dead zone: no towers from any source |
| Dalupirit | 1,783 | 0 | Dead zone: no towers from any source |
| Manraya | 539 | 0 | Dead zone: no towers from any source |
| Pilar | 500 | 0 | Dead zone: no towers from any source |
| Rizal | 482 | 0 | Dead zone: no towers from any source |
| San Nicolas | 390 | 0 | Dead zone: no towers from any source |
| Vinisitahan | 614 | 3 | Crowdsourced signal only (no registered tower) |
| Ward I (Pob.) | 320 | 0 | Dead zone: no towers from any source |
| Ward II (Pob.) | 2,301 | 0 | Dead zone: no towers from any source |
| Ward III (Pob.) | 415 | 0 | Dead zone: no towers from any source |