Longmont, CO ZIP Codes
Longmont, Colorado has 4 ZIP codes: 3 for street addresses (, and ) and 1 for PO boxes ().
Your street decides which one you use.
Which Longmont ZIP code is my address in?
Street ranges from the Census Bureau, 2026. PO box and organization ZIP codes are not found by street. A new street may be missing: address not found?
Longmont ZIP code map
Tap or point to an area to see its ZIP code.Full-size map
80502 has no area on the map: it is a PO box or single-organization ZIP code. Dashed line: Longmont city limits.
Map: Census Bureau ZIP Code Tabulation Areas (2020) and place limits (2024).
All Longmont ZIP codes by type
| ZIP | Type and post office or station |
|---|---|
| 80501 | street delivery Longmont |
| 80502 | PO boxes at the Longmont post office Longmont |
| 80503 | street delivery Longmont |
| 80504 | street delivery Longmont |
Why your mail may say Longmont when you live outside it
Longmont ZIP codes also cover Firestone, Frederick and Niwot, so a letter addressed to Longmont can go to a home outside the city limits.
A ZIP code does not set your city, school district or tax. Boulder County property records show which city you are in.
Longmont ZIP code questions
What is the main ZIP code for Longmont?
80501, the ZIP code of the main Longmont post office at 201 Coffman St.
Which Longmont ZIP codes are for PO boxes only?
80502. Mail to it goes to boxes at the post office, not to street addresses.
What county is Longmont in?
Boulder County, with parts in Weld County.
ZIP codes for towns near Longmont
More towns near Longmont: Thornton, Westminster, Brighton, Arvada, Windsor, Greeley, Commerce City, Fort Collins, Wheat Ridge.
Sources and last checked
USPS ZIP Locale Detail (October 1, 2026), GeoNames (CC BY 4.0), U.S. Census Bureau, HUD-USPS crosswalk.
Checked October 20, 2026. Sources · How we build our lists · Corrections