Kennebec County, Maine has 34 ZIP codes in this list, from 04259 to 04989. They cover 29 places, among them Augusta, Waterville, Monmouth and North Monmouth.
The ZIP code areas of Kennebec County add up to about 857 square miles of land (2,220 sq km) as the Census Bureau draws them. The largest is 04330 (Augusta), with 117 square miles.
Places with more than one code here: Augusta (5 codes), Waterville (2 codes).
Using these codes
In an address, the ZIP code comes last, after the city and the two-letter state: Monmouth, ME 04259.
Tap a ZIP code to open it in the look-up, with a copy button for the address line.
A code can cross a county line, and one town can have several codes. The table shows the main place of each code.
"No area" means the Census Bureau draws no area for that code. Such codes are usually for post office boxes or a single building.
Places and counties: GeoNames. Areas: U.S. Census Bureau, 2024 ZIP Code Tabulation Areas. Checked in November 2026. This site is not connected with the United States Postal Service; for mailing, confirm the address with USPS.
ZIP Codes