Jefferson County, MT demographics:
population, income, and more

Total population
12,774
2.2% year-over-year change
Median household income
$95,490/yr
24.7% year-over-year change
Housing units
5,407
0.3% year-over-year change

Jefferson County population

How many people live in Jefferson County

Jefferson County is home to 12,774 residents, according to the most recent Census data. Gender-wise, 50.6% of Jefferson County locals are male, and 49.4% are female.

Total population
12,774
2.2% year-over-year change
Gender ratio
Male
50.6%
6,459
Female
49.4%
6,315
Value Percent YoY change
Male 6,459 50.6% 1.9%
Female 6,315 49.4% 2.5%
A higher population often means more rental variety and livelier areas. The gender balance—how many men live here compared to women—can reveal a lot about the community and the lifestyles of its residents. Use this info to get a sense of the area's pace and personality.

Age demographics

The median age in Jefferson County is 47, with the population distributed as follows: about 15.8% are children under 15, then 10.4% are in the 15 to 24 age group. Adults between 25 and 44 make up 21.6% of the population, while another 29% fall into the 45 to 64 bracket. Finally, around 23.2% are 65 or older.

Median age
47.1
Age breakdown
Under 15
15.8%
15 to 24
10.4%
25 to 44
21.6%
45 to 64
29%
Over 65
23.2%
Value Percent YoY change
Under 15 2,025 15.8% 1.8%
15 to 24 1,323 10.4% -0.3%
25 to 44 2,762 21.6% 5.5%
45 to 64 3,703 29% -0.4%
Over 65 2,961 23.2% 4.0%
The age composition helps you get insight into who lives in the area. A younger population might mean a more active, fast-paced vibe, while an older one could suggest a quieter, slower lifestyle. If there's a balanced makeup, you’re likely to find a variety of services, housing types, and community spaces that cater to different life stages.

Racial makeup

In Jefferson County, 98.4% of the population are US-born citizens, while 1.3% have gained naturalized citizenship. At the same time, 0.2% of residents are non-citizens. There’s also a share of 5.5% that includes residents with two or more races.

Citizenship
U.S.-born citizens
98.4%
Non-U.S.-born citizens
1.3%
Non-citizens
0.2%
Value Percent YoY change
U.S.-born citizens 12,572 98.4% 3.5%
Non-U.S.-born citizens 171 1.3% -26.3%
Non-citizens 31 0.2% -74.2%
Racial breakdown
White
91.7%
Black or African American
0%
American Indian and Alaska Native
1.5%
Asian
0.4%
Native Hawaiian and other Pacific Islander
0%
Two or more races
5.5%
Other
0.9%
Value Percent
White 11,717 91.7%
Black or African American 4 0%
American Indian and Alaska Native 188 1.5%
Asian 50 0.4%
Two or more races 698 5.5%
Other 117 0.9%

Households in Jefferson County

A peek inside Jefferson County households

Jefferson County has 4,996 households, with an average of 2 members in each. Of these, 74.8% are families, while the remaining 25.2% are made up of individuals living alone or with non-relatives, such as roommates.

Households stats

Total households
4,996
2.2% year-over-year change
Average people per household
2
Non-family households
1,261
Family households
3,735
Value Percent YoY change
Non-family households 1,261 25.2% -0.9%
Family households 3,735 74.8% 3.3%
The mix between family and non-family households gives a glimpse into daily life. A higher percentage of families might mean more parks and schools, while more non-family setups can mean flexible housing and diverse living styles. For renters, this can signal what kinds of homes are common and can help you figure out if the area matches your lifestyle.

Housing in Jefferson County

The housing landscape of Jefferson County

Jefferson County's housing consists of 5,407 units, with 83.2% being detached single-family homes ideal for those wanting space. Attached options, including duplexes and townhouses, make up 2.2% and offer a more compact, shared living style. Then there are the multifamily buildings in the area, and for those seeking flexibility, non-traditional options like mobile homes account for 11.3% of the housing landscape.

Housing units
5,407
0.3% year-over-year change
Housing types
Value Percent
1 unit, detached 4,500 83.2%
1 unit, attached 117 2.2%
2 units 50 0.9%
3 or 4 units 19 0.4%
5 to 9 units 18 0.3%
10 to 19 units 49 0.9%
Mobile home 613 11.3%
Boat, RV, van, etc. 41 0.8%
Homes built since 2020
185
131.2% year-over-year change

The age of buildings in Jefferson County

In Jefferson County, the median construction year is 1990. About 10.1% of homes were built before the 1940s, with another 1.8% going up by 1949. Most development happened in the second half of the 20th century. Then, 16.6% of homes were added from 2000 to 2009, 10.6% between 2010 and 2019, and 3.4% are part of the newest wave of development.

Construction year breakdown by decade
Value Percent YoY change
Built in 1939 or earlier 547 10.1% -1.6%
Built between 1940 and 1949 95 1.8% -36.7%
Built between 1950 and 1959 250 4.6% -7.4%
Built between 1960 and 1969 255 4.7% -4.8%
Built between 1970 and 1979 1,049 19.4% -0.8%
Built between 1980 and 1989 468 8.7% 12.0%
Built between 1990 and 1999 1,088 20.1% 5.9%
Built between 2000 and 2009 897 16.6% -2.5%
Built between 2010 and 2019 573 10.6% -10.6%
Built in 2020 or later 185 3.4% 131.2%
As a renter, knowing when homes were built helps you understand the potential condition and design of rental units. Newer builds may have more contemporary layouts, while older homes can offer character or larger lots, depending on the area.

Jefferson County occupancy rates

Out of the 4,996 occupied housing units in Jefferson County, 84.2% are owner-occupied, while 15.8% are lived in by tenants. Meanwhile, 7.6% of all homes on the local market sit vacant.

Occupied housing units
4,996
2.2% year-over-year change
Occupancy breakdown
Renter occupied
790
Owner occupied
4,206
Value Percent YoY
change
Renter occupied 790 15.8% -4.2%
Owner occupied 4,206 84.2% 3.5%
Unoccupied housing units
7.6%
Unoccupied housing units refer to homes that are currently without residents—whether they're waiting for renters or owners, used seasonally, or simply unclaimed. A higher share of empty homes may mean more housing availability, while a low number can reflect a tighter market with more competition. This, along with the renter-vs.-owner mix, helps paint a clearer picture of what types of housing and services are likely to be available in the area.

Jefferson County housing costs

Housing costs in Jefferson County come to a median of $1,183 per month, while tenants specifically pay a median gross rent of $925.

Median housing costs per month
$1,183/month
This figure sums up typical monthly housing costs for all households in the area. If you own, it includes mortgage payments in addition to property taxes, insurance and HOA fees. If you rent, it accounts for rent plus extras like utilities. It’s useful for seeing how local living expenses stack up compared to other places.
Median gross rent in Jefferson County
$925/month
Gross rent gives a more complete look at what renters actually pay, including not just base rent, but also utilities and fees. It’s a key number for evaluating rental affordability in your area of interest and understanding how it compares to nearby locations.

Education in Jefferson County

Jefferson County education at a glance

About 34.2% of the population in Jefferson County went to high school, while 20.8% pursued college studies. Another 11.7% earned an associate degree and 19.1% hold a bachelor’s. Meanwhile, 11.5% went even further, earning a master’s or doctorate.

Education level
Value Percent YoY change
No high school 277 2.7% 15.4%
High school diploma 3,500 34.2% 10.3%
College diploma 2,130 20.8% -5.1%
Associate degree 1,192 11.7% -5.2%
Bachelor's degree 1,949 19.1% -2.8%
Graduate degree 1,171 11.5% 11.0%
A community’s education mix can offer insights into the local economy and housing market. Higher levels of education often align with more job opportunities and stable incomes, which can increase demand for homes and influence both rent prices and rental availability.

Income in Jefferson County

How much people earn in Jefferson County

The average annual household income in Jefferson County was $123,428 in 2024, the most recent annual data available, according to the U.S. Census Bureau. This marked a +14.7% change from the previous year. At the same time, the median income stood at $95,490, reflecting a +24.7% shift over the same period.

Average household income in Jefferson County
$123,428/year
14.7% year-over-year change
Median household income in Jefferson County
$95,490/year
24.7% year-over-year change

Jefferson County income by age

In Jefferson County, households led by residents aged 25 to 44 — usually in the early to mid stages of their careers — have a median income of $109,135. Those with someone between 45 and 64 in charge, often well established professionally, earn $125,070 overall. Overall, 94.3% of the locals in this community live above the poverty line.

Income breakdown by age
Value YoY change
25 - 44 $109,135 37.8%
45 - 64 $125,070 22.2%
Over 65 $61,434 3.8%
Above poverty level
11,742
Below poverty level
715
Value Percent YoY
change
Above poverty level 11,742 94.3% 2.9%
Below poverty level 715 5.7% -7.3%

Employment in Jefferson County

Workforce and job types in Jefferson County

The job market in Jefferson County is powered by 6,175 working residents, spread across a range of industries and roles. 79.8% of the working population are employed in professional or administrative positions, while 20.2% are in hands-on or service-based jobs. Also, 13.7% run their own businesses, 50.1% are employed by private companies, and 24% work in the public sector.

Workforce demographics

Working population
6,175
5.8% year-over-year change
White collar
4,928
Blue collar
1,247
Value Percent YoY change
White collar 4,928 79.8% 8.7%
Blue collar 1,247 20.2% -4.3%
Employer type
Self employees
13.7%
Private companies
50.1%
Governmental workers
24%
Not for profit companies
12.3%
Value Percent YoY change
Self employees 845 13.7% -3.5%
Private companies 3,091 50.1% 4.3%
Governmental workers 1,481 24% 1.9%
Not for profit companies 758 12.3% 39.1%
Unemployment rate
4.2%
57.9% year-over-year change

Available workforce

The unemployment rate in Jefferson County stands at 4.2%, representing the share of the workforce currently without a job and actively looking for one.

For renters, the unemployment rate helps paint a picture of job security and financial stability in the area. Rates around 4% to 5% are considered typical. A lower-than-average rate might suggest strong job prospects and a thriving local economy, while a higher rate could hint at fewer opportunities—both useful to consider when planning a move.

Transportation in Jefferson County

How people get around in Jefferson County

In Jefferson County, the average commute time is 24 minutes. Commuting methods vary: 84% of residents travel by personal vehicle and 2.2% prefer to walk, while the remaining share relies on public transit or on two wheelers to get from A to B.

Commute time
24 min
Means of transportation
Value Percent YoY change
Car 5,043 84% 6.4%
Bicycle 7 0.1% 16.7%
Walk 135 2.2% -20.1%
Understanding how locals get to work can help you plan your own routine. High car usage might mean you’ll need a vehicle, while strong public transit or walkability could save you the hassle. Commute times also play a big role in quality of life—shorter trips can give you more time for the things you enjoy.

What is the median and average household income in Jefferson County by zipcode?

Zipcode Population Number of households Median income Average income
59631 375 164 $0 $90,316
59632 2,557 989 $68,750 $96,531
59634 5,521 1,974 $129,891 $166,693
59635 8,292 3,381 $83,740 $101,421
59638 769 271 $126,723 $152,899
59701 34,232 14,888 $60,437 $80,145
59721 423 190 $94,167 $137,869
59759 3,631 1,630 $60,571 $76,388

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FAQs about Jefferson County demographics 

What is the total population of Jefferson County?

Jefferson County has a total population of 12,774 residents, according to the latest release from the U.S. Census Bureau: the 2019-2023 American Community Survey (ACS) 5-year estimates. This figure changed by +2.2% compared to a year ago.

What is the gender ratio in Jefferson County?

The gender ratio in Jefferson County is as follows:
  • 50.6% males (6,459 residents)
  • 49.4% females (6,315 residents)

What is the median age in Jefferson County?

The median age in Jefferson County is 47.1.

What is the age distribution of the population in Jefferson County?

The age distribution in Jefferson County is as follows:
  • Under 15: 15.8% (2,025 residents)
  • Ages 15-24: 10.4% (1,323 residents)
  • Ages 25-44: 21.6% (2,762 residents)
  • Ages 45-64: 29% (3,703 residents)
  • Over 65: 23.2% (2,961 residents)

What is the racial and ethnic makeup of Jefferson County?

The racial and ethnic makeup of Jefferson County is as follows:
  • White: 91.7% (11,717 residents)
  • Black or African American: 0% (4 residents)
  • American Indian and Alaska Native: 1.5% (188 residents)
  • Asian: 0.4% (50 residents)
  • Native Hawaiian and Other Pacific Islander: 0% (0 residents)
  • Two or More Races: 5.5% (698 residents)
  • Other: 0.9% (117 residents)

What percentage of the population in Jefferson County are U.S.-born citizens?

U.S.-born citizens represent 98.4% of the population in Jefferson County.

How many housing units are there in Jefferson County?

There are 5,407 housing units in Jefferson County, reflecting a +0.3% change compared to the previous year, according to the latest data from the U.S. Census Bureau.

How many households are in Jefferson County and what is the average household size?

Jefferson County has a total of 4,996 households, with an average of 2 people in each.

What is the median household income in Jefferson County?

Jefferson County has a median household income of $95,490, representing a +24.7% shift from the previous year, according to the U.S. Census Bureau.

What is the employment rate and job market overview for Jefferson County?

The employment rate is 95.8% in Jefferson County, with a workforce of 6,175 residents. Here’s a detailed breakdown of the local job market:

Job types:
  • White-collar workers: 79.8% (4,928 residents)
  • Blue-collar workers: 20.2% (1,247 residents)

Places of employment:
  • Self-employed: 13.7% (845 residents)
  • Private companies: 50.1% (3,091 residents)
  • Governmental workers: 24% (1,481 residents)
  • Not-for-profit companies: 12.3% (758 residents)

Data source & methodology

The demographic data on this page was sourced from the latest U.S. Census Bureau release—the 2019–2023 American Community Survey (ACS) 5-year estimates.

The information, issued annually, is compiled and published by the Point2Homes Research Team as soon as new data becomes available.

No representation, guarantee, or warranty is made concerning the accuracy or completeness of modified or aggregated information for particular areas.

Page last updated: September 2025