Jefferson County, Montana Demographics 2026
Jefferson County, Montana has a population of 12,774, the 16th most populous county in Montana. The median household income is $95,490 and the median home value is $446,900. The poverty rate is 5.7%.
Data vintage: U.S. Census Bureau ACS 2020–2024 5-Year Estimates · refreshed July 2026 · Methodology & source notes
Jefferson County Quick Facts
How Jefferson County Changed
Change from the 2019–2023 ACS period to 2020–2024. These are rolling five-year estimates, not year-over-year measurements.
| Metric | 2019–2023 | 2020–2024 | Change |
|---|---|---|---|
| Population | 12,501 | 12,774 | +2.2% |
| Median household income | $76,576 | $95,490 | +24.7% |
| Median home value | $408,000 | $446,900 | +9.5% |
Median Household Income
Median Home Value
Economy & Housing
Household Income Distribution
Detailed income brackets
Employment
Housing Overview
People & Demographics
Age Distribution
Race & Ethnicity
Diversity Index
A less diverse community where one racial or ethnic group represents a large majority.
State average: 29 | National average: 61
Education
Educational Attainment (Adults 25+)
Cities & Places in Jefferson County
| City | Population | Median Income | Poverty | Home Value |
|---|---|---|---|---|
| Montana City | 3,092 | $129,755 | 1.8% | $571,200 |
| Clancy | 1,874 | $125,000 | 4.8% | $469,300 |
| Boulder | 1,284 | $72,500 | 3.8% | $212,300 |
| Whitehall | 1,156 | $44,844 | 20.6% | $194,100 |
| South Hills | 620 | $168,235 | 1.0% | $703,800 |
| Jefferson City | 533 | $125,682 | 0.0% | N/A |
| Basin | 352 | $46,597 | 14.4% | $227,700 |
| Rader Creek | 310 | $100,691 | 4.8% | $463,200 |
| Elkhorn | 34 | N/A | 0.0% | N/A |
| Cardwell | 30 | N/A | 13.3% | N/A |
Explore Montana Rankings
Population Overview
Jefferson County is located in Montana with a total population of 12,774. It is the 16th most populous county out of 56 in Montana. The county encompasses 10 Census-designated places.
Age Demographics
The median age in Jefferson County is 47.1 years. This is 17% higher than the state median of 40.4 years.
Economy, Income & Housing
The median household income in Jefferson County is $95,490. This is 32% higher than the state median of $72,509. It is also 18% higher than the national median of $80,734. The poverty rate stands at 5.7%. This is 50% lower than the state poverty rate of 11.5%. The unemployment rate is 4.2%. This is 16% higher than the state rate of 3.6%. The median home value is $446,900. Housing costs are 19% higher than the state median of $375,800. The home-value-to-income ratio is 4.7x. 84.2% of occupied housing units are owner-occupied. This homeownership rate is 22% higher than the state average of 69.2%.
Race & Ethnicity
Jefferson County has a predominantly White (non-Hispanic) population, comprising 90.6% of all residents. Hispanic or Latino residents account for 3.0%. The Black or African American population (0.0%) is well below the state average of 0.4%. The Asian population (0.4%) is well below the state average of 0.8%.
Education
32.2% of residents aged 25 and older hold a bachelor's degree or higher. This is 9% lower than the state rate of 35.2%. Nationally, 35.7% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 93.9%.
Data Sources & Methodology
All figures for Jefferson County come from the U.S. Census Bureau's American Community Survey (ACS) 2020–2024 5-Year Estimates, with comparisons drawn against Montana and national averages from the same dataset. See our methodology page for how each metric is defined, or data.census.gov for official tables with margins of error.
Frequently Asked Questions
What is the population of Jefferson County, Montana?
Jefferson County has a population of 12,774, making it the 16th most populous county in Montana.
What is the median income in Jefferson County?
The median household income in Jefferson County is $95,490 with a poverty rate of 5.7%.
How many cities are in Jefferson County, Montana?
Jefferson County contains 10 Census-designated places.