| City: | Knoxville, Maryland |
| City Alias: | Brunswick, Rosemont |
| Counties: | Frederick County [Primary] Washington County |
| Timezone: | Eastern (GMT -05:00) |
| Local Time: | 12:35:33 AM |
| Population: | 4,809 [See All] |
| Area Codes: | 227 / 240 / 301 / 324 / 369 |
| Classification: | Standard [Normal Street Delivery] |
| Coordinates: | 39.3616, -77.6619 |
| Land Area: | 32.018 sq mi |
| Quick Link: |
ZIP Code 21758 has 4,809 residents and 1,747 households (average 2.75 persons per household). The median age is 43.2 years, older than the state (38.8) and older than the nation (38.8). The gender split is 51.0% male and 49.0% female, which is slightly higher than the state male share (48.2%), making this a male-majority area. Largest groups are White (82.9%, much higher than the state average of 48.7% and well above the national average of 61.6%) and Black or African American (6.2%, much lower than the state average of 29.5%); Hispanic or Latino residents make up 5.6%, which is much lower than the national average (18.7%).
Explore More: Population Over Time By Age & Gender By Race By Gender Nativity & Citizenship
| 2020 Population: | 4,809Source: Census DHC |
| 2023 ACS Population Estimate: | 4,238Source: Census ACS |
| 2025 ZC Population Estimate: | 5,054Source: ZIP-Codes.com |
| Population Density: | 150.2 people per sq mile |
| Average Income: | $110,694Source: Census ACS |
| Households: | 1,747Source: Census DHC |
| Average House Value: | $388,200Source: Census ACS |
| Persons Per Household: | 2.75Source: Census DHC |
| Average Family Size: | 2.77Source: Census ACS |
| Group | 2010 | 2011 | 2102 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Census ACS Population Estimate | -- | 5,426 | 5,005 | 4,909 | 4,759 | 4,909 | 4,705 | 4,844 | 4,912 | 5,127 | 4,616 | 4,454 | 4,610 | 4,238 |
| Decennial Census | 4,921 | -- | -- | -- | -- | -- | -- | -- | -- | -- | 4,809 | -- | -- | -- |
Median Age: 43.2
Male Median Age: 42.6
Female Median Age: 44
| Group | < 5 | 5-9 | 10-14 | 15-19 | 20-24 | 25-29 | 30-34 | 35-39 | 40-44 | 45-49 | 50-54 | 55-59 | 60-64 | 65-69 | 70-74 | 75-79 | 80-84 | 85+ |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Male | 156 | 161 | 183 | 170 | 140 | 90 | 122 | 141 | 134 | 204 | 174 | 231 | 173 | 151 | 86 | 68 | 34 | 33 |
| Female | 144 | 154 | 166 | 159 | 89 | 85 | 129 | 145 | 142 | 168 | 192 | 182 | 169 | 165 | 106 | 80 | 39 | 44 |
| Total | 300 | 315 | 349 | 329 | 229 | 175 | 251 | 286 | 276 | 372 | 366 | 413 | 342 | 316 | 192 | 148 | 73 | 77 |
| White: | 3,988 | 84.80% |
| Black: | 299 | 6.36% |
| Hispanic:* | 267 | 5.68% |
| Asian: | 72 | 1.53% |
| American Indian: | 11 | 0.23% |
| Hawaiian: | 0 | 0% |
| Other: | 66 | 1.40% |
| Total: | 4,703 | 100% |
| Gender | Count | % | Median Age |
|---|---|---|---|
| Males: | 2,451 | 50.97% | 42.6 years |
| Females: | 2,358 | 49.03% | 44.0 years |
| Total: | 4,809 | 100% | 43.2 years |
| Native, born in the United States: | 3,821 | 90.16% |
| Native, born in PR, Island Areas, or abroad: | 68 | 1.60% |
| Foreign born, naturalized U.S. citizen: | 255 | 6.02% |
| Foreign born, not a U.S. citizen: | 94 | 8.24% |
| Total Population: | 4,238 | 100% |
| Total Native Population: | 3,889 | 91.76% |
| Total Foreign-born Population: | 349 | 8.24% |
In 2023, the Median household income is $110,694, which is much higher than the national median ($78,538), is up $19,263 (21.1%) since 2011 and above its 2019 pre-pandemic level by $29,819. Family households earn a median of $130,592 versus $55,938 for nonfamily households (a difference of $74,654). By gender, male median income is $90,708 and female is $87,396, which is much higher than the national female median ($53,445), with a current gap of $3,312 that has narrowed from 2011 to 2023. The labor-force participation rate is 69.0%, which is higher than the national rate (63.5%). The unemployment rate is 7.1%, which is far worse than the state rate (4.9%). The largest occupation group is Management (49.9%).
Explore More: Income Over Time Household Income Employment Status By Occupation
| Income Type | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Median Household Income | $91,431 | $88,810 | $88,274 | $83,850 | $82,548 | $76,739 | $69,306 | $73,207 | $80,875 | $100,921 | $96,863 | $103,081 | $110,694 |
| Median Family Income | $92,391 | $92,500 | $94,760 | $89,112 | $88,605 | $88,051 | $91,354 | $88,148 | $108,456 | $122,500 | $123,500 | $114,783 | $130,592 |
| Median NonFamily Income | $34,097 | $43,333 | $33,882 | $47,250 | $33,969 | $36,318 | $29,946 | $54,102 | $49,195 | $52,903 | $57,396 | $61,194 | $55,938 |
| Median Male Income | $80,117 | $72,833 | $59,038 | $57,500 | $55,000 | $52,198 | $53,073 | $60,769 | $61,495 | $59,367 | $79,844 | $83,667 | $90,708 |
| Median Female Income | $51,376 | $53,441 | $54,035 | $50,238 | $43,365 | $48,631 | $48,698 | $52,109 | $54,020 | $57,143 | $74,191 | $81,895 | $87,396 |
| Employed: | 2,090 | 63.68% |
| Unemployed: | 161 | 4.91% |
| Not In Labor Force: | 1,031 | 31.41% |
| Total: | 3,282 | 100% |
| Management, business, science, and arts: | 1,043 | 49.90% |
| Service: | 309 | 14.78% |
| Sales and Office: | 293 | 14.02% |
| Natural resources, construction, and maintenance: | 162 | 7.75% |
| Production, transportation, and material moving: | 283 | 13.54% |
| Total Civilian Employed Population: | 2,090 | 100% |
In 2023, the median home value is $388,200, which is markedly greater than the national median ($303,400), is up $89,500 (29.96%) since 2011 and above its 2019 pre-pandemic level by $107,700. The median gross rent is $1,696, which is much higher than the national median ($1,348), is up $711 (72.18%) since 2011 and above its 2019 pre-pandemic level by $352. Of occupied housing, owners make up 88.13% (67.61% with a mortgage, 32.39% free-and-clear) and renters 11.87% - making this ZIP Code more home ownership than the state and under national rental averages. The vacancy rate is 4.25%, which is much lower than the national rate (10.43%).
Explore More: Compare Home Value Home Value Over Time Rent & Over Time Housing Occupancy
| Group | 2011 | 2102 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Median Home Value | $298,700 | $279,700 | $258,700 | $252,100 | $248,900 | $261,200 | $275,100 | $253,300 | $280,500 | $298,700 | $309,600 | $338,000 | $388,200 |
| Less than $500: | 0 | 0.00% |
| $500 to $999: | 34 | 17.89% |
| $1,000 to $1,499: | 37 | 19.47% |
| $1,500 to $1,999: | 46 | 24.21% |
| $2,000 to $2,499: | 61 | 32.11% |
| $2,500 to $2,999: | 0 | 0.00% |
| $3,000 or more: | 0 | 0.00% |
| No Rent: | 12 | 6.32% |
| Total: | 190 | 100% |
| Group | 2011 | 2102 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Median Rent | $985 | $1,069 | $1,117 | $1,225 | $1,235 | $1,300 | $1,332 | $1,464 | $1,344 | $1,532 | $1,559 | $1,688 | $1,696 |
| Owner Occupied (with mortgage): | 954 | 59.59% |
| Owner Occupied (free and clear, no mortgage): | 457 | 28.54% |
| Renter Occupied: | 190 | 11.87% |
| Total Occupied Housing Units: | 1,601 | 100% |
| Occupied Housing Units: | 1,601 | 95.75% |
| Vacant Housing Units (not graphed): | 71 | 4.25% |
| Total Housing Units: | 1,672 | 100% |
| Single-Family Units: | 1,654 | 98.92% |
| Multi-Family Units: | 18 | 1.08% |
| Other Units: | 0 | 0.00% |
| Total Housing Units: | 1,672 | 100% |
In 2023, 42.30% of adults (25+) have a bachelor's degree or higher, which is comparable to the national rate (35.00%). High school or higher is 93.10%, which is well above the national rate (89.40%). The uninsured rate is 2.40%, which is far lower than the national rate (8.60%). The share of people in poverty is 2.40%, which is far lower than the national rate (8.70%), down 0.10 percentage points since 2011 and below its 2019 pre-pandemic level by 0.70 percentage points. Poverty has been broadly stable, which may reflect structural barriers or offsetting gains and setbacks. Among residents ages 3+, the largest enrollment group is elementary (54.58%). College enrollment is 15.85%, which is markedly below the state rate (28.00%), indicating the community may be more oriented toward vocational/trade or direct-to-workforce opportunities.
Explore More: Educational Attainment Health Insurance Poverty Over Time School Enrollment
| Less than 9th grade: | 101 | 3.37% |
| 9th to 12th grade, no diploma: | 106 | 3.54% |
| High school graduate (includes equivalency): | 1,006 | 33.61% |
| Some college, no degree: | 310 | 10.36% |
| Associate's degree: | 205 | 6.85% |
| Bachelor's degree: | 614 | 20.51% |
| Graduate or professional degree: | 651 | 21.75% |
| Total: | 2,993 | 100% |
| High school or higher: | 2,786 | 93.08% |
| Bachelor's degree or higher: | 1,265 | 42.27% |
| Private Insurance: | 3,496 | 72.05% |
| Public Insurance: | 1,254 | 25.85% |
| No Insurance: | 102 | 2.10% |
| Total: | 4,852 | 100% |
| Has Health Insurance: | 4,750 | 97.90% |
| Group | 2011 | 2102 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| % of People in Poverty | 2.5% | 3.4% | 4.6% | 3.8% | 5.8% | 5.5% | 4.7% | 2.6% | 3.1% | 3.3% | 3.4% | 2.4% | 2.4% |
Note: Counts of Families & People in poverty are not published at the ZIP Code level due to small sample sizes. Percentages shown are survey estimates from the American Community Survey (ACS). They may differ from official poverty statistics. The U.S. Census Bureau defines poverty status by comparing a family's or individual's total income with federal poverty thresholds that vary by family size and composition.
| Nursery School, Preschool: | 43 | 4.80% |
| Kindergarten: | 37 | 4.13% |
| Elementary school (grades 1-8): | 489 | 54.58% |
| High school (grades 9-12): | 185 | 20.65% |
| College or graduate school: | 142 | 15.85% |
| Total: | 896 | 100% |
| Early Childhood: | 80 | 8.93% |
| K-12 (Primary & Secondary School): | 711 | 79.35% |
ZIP Code 21758 supports both business and residential activity. According to the Business Census (2023), there are 59 business establishments, employing about 402 people with an annual payroll of $16,270,000. USPS data shows 1,838 residential mailboxes and 29 business mailboxes, reflecting local delivery coverage.
| # Residential Mailboxes: | 1,838Source: USPS |
| # Business Mailboxes: | 29Source: USPS |
| Total Delivery Receptacles: | 1,872Source: USPS |
| Single Family Delivery Units: | 1,563Source: USPS |
| Multi Family Delivery Units: | 0Source: USPS |
| # of Businesses: | 59Source: CBP |
| 1st Quarter Payroll: | $3,895,000Source: CBP |
| Annual Payroll: | $16,270,000Source: CBP |
| # of Employees: | 402Source: CBP |
ZIP Code 21758 is located in Frederick County, Maryland, within the Washington-Arlington-Alexandria, DC-VA-MD-WV Metropolitan Statistical Area (CBSA 47900) and Maryland's 6th Congressional District. This Metro area has a population of 6,263,796 people, about 0.08% of whom live in ZIP Code 21758, and is subdivided into the Frederick-Gaithersburg-Bethesda, MD division. It covers 32.018 sq mi of land and a water area of 2.828 sq mi.
| CBSA Name: | Washington-Arlington-Alexandria, DC-VA-MD-WVSource: Census |
| CBSA Number: | 47900Source: Census |
| CBSA Type: | MetroSource: Census |
| CBSA Division: | Frederick-Gaithersburg-Bethesda, MD (CBSA Div 23224)Source: Census |
| CBSA Population: | 6,263,796Source: Census |
| MSA: | Washington-Baltimore, DC-MD-VA-WV CMSASource: Census |
| Land Area: | 32.018 sq miSource: Census |
| Water Area: | 2.828 sq miSource: Census |
| Congressional District: | 06Source: USPS |
| Congressional Land Area: | 1950.26 sq miSource: Census |
| PMSA: | Washington, DC-MD-VA-WV PMSASource: Census |
| Intro Date: | < 2004-10Source: ZIP-Codes.com |
| Place FIPS Code: | --Source: Census |
| Place Name: | --Source: Census |
ZIP Code 21758 is in the Washington County Public Schools, which serves grades Pre-Kindergarten thru 12th. There are 1 public school(s) in this ZIP Code, and we have located 3 private school(s). It also has 6 colleges, universities or post secondary education institutions nearby which would be a short commute to.
Our sources include trusted federal and licensed data from the United States Postal Service, U.S. Census Bureau, U.S. Geological Survey, Centers for Medicare & Medicaid Services, and the National Center for Education Statistics, along with proprietary datasets created by ZIP-Codes.com. Data last updated on October 1, 2025.