Los Alamos County
New Mexico · County seat: Los Alamos · Active county or equivalent
FIPS code 35028 is Los Alamos County, New Mexico. With a population of 19,253 (2022 ACS estimate), it ranks #20 in New Mexico and #1910 nationally. Los Alamos County is part of the Los Alamos, NM. The state FIPS code for New Mexico is 35. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.
County FIPS
35028
Population
19,253
2022 ACS · #1910 nationally
Density
176.4/mi²
people per sq mile
Land Area
109
sq miles
Urban/Rural
Nonmetro — urban 2.5K–19.9K, adjacent to metro
RUCC 6
How This FIPS Code Works
The 5-digit FIPS code 35028 is formed by combining the 2-digit state identifier 35 (New Mexico) with the 3-digit county identifier 028. Together they uniquely identify Los Alamos County in every US federal dataset. No two counties share the same 5-digit FIPS code.
Census ACS Data for FIPS 35028
From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 35028.
Median Household Income
$135,801
ACS B19013_001E
Poverty Rate
3.7%
ACS B17001 (below poverty level)
Median Age
41.2
ACS B01002_001E
Metropolitan Area
Adjacent Counties (3)
Counties that share a border with Los Alamos County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 35028.
Federal Datasets Using Code 35028
FIPS code 35028 appears as the county identifier in the following federal datasets. Analysts joining data across these sources use this code as the common geographic key.
Using FIPS Code 35028 in Code
Common patterns for querying federal datasets by this county's FIPS code. The leading zeros are significant — always treat FIPS codes as strings, not integers.
import requests
url = "https://api.census.gov/data/2022/acs/acs5"
params = {
"get": "NAME,B19013_001E,B01003_001E",
"for": "county:028",
"in": "state:35",
"key": "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json() # [[header...], [Los Alamos County, New Mexico, income, pop, ...]
-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '35028';
-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '35'
AND county_fips = '028';
-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 35028 is WRONG for this county
library(tidycensus)
get_acs(
geography = "county",
variables = c(income = "B19013_001E", pop = "B01003_001E"),
state = "35",
county = "028",
year = 2022
)
ZIP Codes in Los Alamos County
ZIP codes do not align perfectly with county boundaries — a single ZIP code can span multiple counties, and a county can contain parts of many ZIP codes. The ratios below (from the Census 2020 ZCTA relationship file) show the land area share of each ZCTA that falls within Los Alamos County. Why FIPS ≠ ZIP →
| ZIP Code | % in county |
|---|---|
| 87547 | 100.0% |
| 87544 | 42.4% |