Jefferson County, Montana
Located in Montana, Jefferson County has a population of 12,774 residents and a median age of 47.1 years, making it the #2,300 most populous county out of 3,222 nationwide. In terms of economic indicators, the county has a poverty rate of 5.7%. The median home value is $446,900, and the median household income is $95,490, which is 27% above the national median.
Demographics
Jefferson County has a population of 12,774, making it the #2,300 most populous county in the US. The median age is 47.1 years, which is 21.1% above the national median.
Population Trend
Rankings →Year-over-Year Population Growth
Age & Sex Distribution
Race & Ethnicity
Nativity
Geographic Mobility (Past Year)
Economy
The median household income in Jefferson County is $95,490, ranking #217 out of 3,222 counties — 27.1% above the national median. The poverty rate is 5.7% and unemployment stands at 4.2%.
Median Household Income Trend
Rankings →Income Distribution
Industry of Employment
Occupation
Housing
The median home value in Jefferson County is $446,900 (+58.5% vs national). Renters pay a median of $925/mo and the homeownership rate is 84.2%.
Median Home Value Trend
Rankings →Household Type
Education
In Jefferson County, 32.2% of adults age 25+ hold a bachelor's degree or higher, which is 4.6% below the national average, ranking #619 out of 3,222 counties.
Bachelor's Degree or Higher Trend
Rankings →Health & Wellbeing
Life expectancy in Jefferson County is 76.3 years. 13.8% of adults report poor or fair health and 9.7% lack health insurance. Data from County Health Rankings (2025).
Life Expectancy Trend
Substance Use
13.7% of adults in Jefferson County smoke , 29.4% are obese , and 25.8% report excessive drinking.
Adult Smoking Trend
Safety
The suicide rate is 38.6 per 100,000. Motor vehicle deaths occur at a rate of 14.0 per 100,000.
Suicide Rate Trend
Families & Children
9.6% of children in Jefferson County live in poverty . The teen birth rate is 7.1 per 1,000 females age 15–19.
Teen Birth Rate Trend
Civic & Transportation
Voter turnout in Jefferson County is 86.3%. The mean commute time is 26.4 min, which is 4.3% below the national average.
Voter Turnout Trend
Mean Commute Time Trend
Rankings →Elections
In the 2024 presidential election, Jefferson County voted Republican with a margin of 36.6%. The vote was 30.3% Dem / 66.9% Rep. Compared to 2020, the margin shifted 3.3 toward Republicans .
Vote Share Over Time
About Jefferson County, Montana
Jefferson County, Montana has a total population of 12,774, making it the 2,300th most populous county in the United States. The median age in Jefferson County is 47.1 years, which is 21.1% above the national median of 38.9 years.
The median household income in Jefferson County is $95,490, which ranks #217 of 3,222 counties nationwide. This is 27.1% above the national median of $75,149. The poverty rate is 5.7%, lower than the national rate of 12.6%. The unemployment rate stands at 4.2%.
The median home value in Jefferson County is $446,900, 58.5% above the national median. Renters in Jefferson County pay a median gross rent of $925 per month. The homeownership rate is 84.2%, compared to the national rate of 64.4%.
In Jefferson County, 32.2% of residents aged 25 and older hold a bachelor's degree or higher, 4.6% below the national average of 33.7%. Health insurance coverage stands at 94.2% of the population. The average commute time for workers is 26.4 min.
Jefferson County is a diverse community. The largest racial or ethnic group is White (non-Hispanic) at 90.6% of the population, followed by Two or More Races (4.4%) and Hispanic or Latino (3.0%).
All data for Jefferson County, Montana comes from the U.S. Census Bureau's American Community Survey (ACS) 5-Year Estimates. These figures are estimates based on survey sampling and are subject to margin of error. For the most detailed and up-to-date data, visit the Census Bureau's official data portal.