COUNTY · NM
Los Alamos County, New Mexico
Los Alamos County is a county in New Mexico with FIPS code 35028 and an estimated population of 19,444 (Census 2023), 20th largest of 33 in the state.
County facts
- Name
- Los Alamos County
- State
- New Mexico
- Type
- county
- FIPS code
- 35028
- State FIPS
- 35
- Population (2023)
- 19,444
- Change since 2020
- +0.1%
- State rank
- 20 of 33
Population is the Census Bureau’s Vintage 2023 estimate.
Questions
What is the FIPS code for Los Alamos County?
Los Alamos County, New Mexico has the five-digit FIPS code 35028: 35 for the state and 028 for the county.
What state is Los Alamos County in?
Los Alamos County is in New Mexico.
How do I know if an address is in this county?
Use the address lookup. ZIP codes and city names can cross county lines, so an address is the reliable check.
Sources: U.S. Census Bureau geographic reference files; Census Bureau Population Estimates, Vintage 2023. Last reviewed 2026-10-27.