Maine ZIP codes
Maine holds 485 ZIP codes between 03901 and 04992. The tables rank the places and counties with the most codes; the guide below decodes the numbering.
Places with the most ZIP codes in Maine
| Place | ZIP codes |
|---|---|
| Portland | 9 |
| Augusta | 5 |
| Auburn | 3 |
| Lewiston | 3 |
| Freeport | 3 |
| Limestone | 2 |
| Scarborough | 2 |
| Westbrook | 2 |
| South Portland | 2 |
| Castine | 2 |
| Waterville | 2 |
| Bangor | 2 |
| Orono | 2 |
| New Portland | 2 |
| Biddeford | 2 |
| Durham | 1 |
| Danville | 1 |
| East Livermore | 1 |
| East Poland | 1 |
| Greene | 1 |
Maine counties by ZIP count
| County | ZIP codes |
|---|---|
| Cumberland | 52 |
| Penobscot | 47 |
| Aroostook | 44 |
| Hancock | 43 |
| York | 42 |
| Kennebec | 34 |
| Oxford | 32 |
| Washington | 32 |
| Lincoln | 28 |
| Somerset | 26 |
Reading a Maine ZIP code
Maine holds 485 ZIP codes between 03901 and 04992, spread over 16 counties. Portland leads the state with 9 codes, ahead of Augusta with 5. Every code here opens with the digit 0: that opening number is the national postal region Maine belongs to, the next two digits name the sectional center that sorts the mail, and the final two point to the local office. A ZIP+4 suffix narrows delivery to a block face. Boundaries follow carrier routes rather than city limits, which is why Portland spreads across 9 codes while some rural codes cross county lines.
Source: GeoNames postal dataset (CC BY 4.0), snapshot of 2026-07-09. Counts cover standard delivery ZIPs listed for Maine; unique and PO box codes may add to these totals.
Last updated: · Methodology and sources