The following are the zip codes in the municipalities and cities of Cagayan.
| Region | Provinces | City/Municipality | Zip Code |
| Region 2 (Cagayan Valley) | Cagayan | Sta. Teresita | 3512 |
| Region 2 (Cagayan Valley) | Cagayan | Santo Niño | 3525 |
| Region 2 (Cagayan Valley) | Cagayan | Tuao | 3528 |
| Region 2 (Cagayan Valley) | Cagayan | Tuguegarao City | 3500 |
| Region 2 (Cagayan Valley) | Cagayan | Santa Praxedes | 3521 |
| Region 2 (Cagayan Valley) | Cagayan | Sta. Ana | 3514 |
| Region 2 (Cagayan Valley) | Cagayan | Solana | 3503 |
| Region 2 (Cagayan Valley) | Cagayan | Claveria | 3519 |
| Region 2 (Cagayan Valley) | Cagayan | Enrile | 3501 |
| Region 2 (Cagayan Valley) | Cagayan | Gattaran | 3508 |
| Region 2 (Cagayan Valley) | Cagayan | Gonzaga | 3513 |
| Region 2 (Cagayan Valley) | Cagayan | Iguig | 3504 |
| Region 2 (Cagayan Valley) | Cagayan | Lal-lo | 3509 |
| Region 2 (Cagayan Valley) | Cagayan | Lasam | 3524 |
| Region 2 (Cagayan Valley) | Cagayan | Pamplona | 3522 |
| Region 2 (Cagayan Valley) | Cagayan | Peñablanca | 3502 |
| Region 2 (Cagayan Valley) | Cagayan | Piat | 3527 |
| Region 2 (Cagayan Valley) | Cagayan | Rizal | 3526 |
| Region 2 (Cagayan Valley) | Cagayan | Sanchez-Mira | 3518 |
| Region 2 (Cagayan Valley) | Cagayan | Abulug | 3517 |
| Region 2 (Cagayan Valley) | Cagayan | Alcala | 3507 |
| Region 2 (Cagayan Valley) | Cagayan | Allacapan | 3523 |
| Region 2 (Cagayan Valley) | Cagayan | Amulung | 3505 |
| Region 2 (Cagayan Valley) | Cagayan | Aparri | 3515 |
| Region 2 (Cagayan Valley) | Cagayan | Baggao | 3506 |
| Region 2 (Cagayan Valley) | Cagayan | Ballesteros | 3516 |
| Region 2 (Cagayan Valley) | Cagayan | Buguey | 3511 |
| Region 2 (Cagayan Valley) | Cagayan | Calayan | 3520 |
| Region 2 (Cagayan Valley) | Cagayan | Camalaniugan | 3510 |
