Plain

City ZIP codes · Colorado

Longmont, CO ZIP Codes

4 ZIP codes use the postal name Longmont, Colorado (Census 2020 ZCTAs and GeoNames postal codes, October 2026): 3 residential and 1 for PO boxes or a single organization. Median household income runs from $80,911 in 80501 to $113,643 in 80504, 1.4 times as much (Census Bureau, ACS 2020-2024). Longmont's most populous ZIP code is 80504, with 63,451 people (ACS 2020-2024); 11% of its land is in the city of Longmont.

  • ACS2020-24
  • Census2020
  • GeoNames2026

Where are Longmont's ZIP codes?

80501: $81k median household income80503: $114k median household income80504: $114k median household income80504805038050180501: $81k median household income80503: $114k median household income80504: $114k median household income80504805038050180501: $81k median household income80503: $114k median household income80504: $114k median household income805048050380501
The 3 residential ZIP codes named Longmont, shaded by median household income in national fifths (ACS 2020-2024). Select a ZIP to open it. <$54.1k$98.1k+no figure

Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).

How different are Longmont's ZIP codes?

The highest median household income is in 80504 ($113,643), the lowest in 80501 ($80,911). Home values run from $488,800 in 80501 to $755,500 in 80503.

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013, B25077, B01003).

All 3 residential ZIP codes of Longmont

Residential ZIP codes with the postal name Longmont, CO, largest first (ACS 2020-2024); sort by any column
County
80504 Weld County 63,451 671 $114k $592k
80501 Boulder County 44,147 3,500 $81k $489k
80503 Boulder County 35,846 391 $114k $756k

Download the 4 ZIP codes as CSV

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; 2023 Gazetteer land areas (2020 ZCTAs); town names from simplemaps US ZIP Codes (CC BY 4.0) and GeoNames (CC BY 4.0).

PO Box and single-organization ZIP codes in Longmont

1 ZIP code named Longmont has no residential delivery area: post office boxes, or one organization (a large employer, an agency, a university) with its own code. The Census Bureau publishes no figures for them.

Longmont, CO: ZIP codes without a residential area, for PO boxes or one organization (GeoNames postal codes; USPS does not publish openly which is which)
ZIPCounty
80502Boulder County

Source: GeoNames postal codes (CC BY 4.0); a ZIP code with no Census ZCTA has no residential delivery area.

Which counties do Longmont's ZIP codes reach?

Longmont's residential ZIP codes lie in 3 counties: Boulder County (2 ZIP codes mainly there), Larimer County (part of a ZIP code), Weld County (1 ZIP code mainly there).

Which places do Longmont's ZIP codes cover?

A postal name is not a city limit. By the Census Bureau's places, Longmont's residential ZIP codes cover Longmont itself and 3 other places, each listed with the ZIP codes that have at least 5% of their land in it or hold most of the place:

Source: U.S. Census Bureau, 2020 ZCTA-to-place relationship file (shares of land).

Which first three digits do Longmont's ZIP codes use?

The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Every ZIP code of Longmont starts with 805.

Three-digit prefixes of Longmont's ZIP codes, the sectional center for each (USPS labeling list L005, effective October 1, 2026) and how many of the prefix's codes are Longmont's
PrefixSectional centerHereAll codes
805 Denver, CO (SCF 800) 4 42

Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.