21758 ZIP Code
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ZIP code 21758 covers Knoxville, Maryland, with a population of about 4,238 and a median household income of $110,694.
- Population
- 4,238132 per square mile
- Median age
- 41.83.1 points above the US average
- Median household income
- $110,6941.1× the Maryland median
- Poverty rate
- 5.3%7.1 points below the US average
- Typical home value
- $468,018up 21% in five years
- Median rent
- $1,696about the Maryland median
- Degree or higher
- 42.3%7.3 points above the US average
- Homeownership
- 88.1%23.1 points above the US average
- Time zone
- Eastern UTC-05:00observes daylight saving time
- Businesses
- 55
Where 21758 is
Knoxville, Maryland — the area the Census Bureau draws for this ZIP code. ZIP codes are sets of delivery routes rather than areas, so this is the Census approximation of one, not a Postal Service boundary.
People and households
American Community Survey 2019–2023 five-year estimates
| Population | 4,238 |
|---|---|
| Median age | 41.8 |
| Family households | 68.9% |
| Born outside the US | 8.2% |
| Speaks a language other than English at home | 7.4% |
| White (non-Hispanic) | 80.9% |
| Black (non-Hispanic) | 5.4% |
| Asian (non-Hispanic) | 3.6% |
| Hispanic or Latino | 5.9% |
| Veterans | 7.1% |
Income and poverty
American Community Survey 2019–2023 five-year estimates
| Median household income | $110,694 |
|---|---|
| Income per person | $51,885 |
| Poverty rate | 5.3% |
| Households on SNAP or cash assistance | 7.7% |
Household income distribution
| Under $10k | |
|---|---|
| $10–15k | |
| $15–20k | |
| $20–25k | |
| $25–30k | |
| $30–35k | |
| $35–40k | |
| $40–45k | |
| $45–50k | |
| $50–60k | |
| $60–75k | |
| $75–100k | |
| $100–125k | |
| $125–150k | |
| $150–200k | |
| $200k or more |
Income as declared to the IRS
Filed returns rather than survey responses, so this counts tax units and not households.
| Tax returns filed | 2,340 |
|---|---|
| Mean adjusted gross income | $93,662 |
| Returns declaring $200,000 or more | 9.4% |
| Returns, under $25k | 23.9% |
| Returns, $25k–$50k | 17.1% |
| Returns, $50k–$75k | 13.2% |
| Returns, $75k–$100k | 11.1% |
| Returns, $100k–$200k | 25.2% |
| Returns, $200k or more | 9.4% |
Housing
American Community Survey 2019–2023 five-year estimates
| Median home value | $388,200 |
|---|---|
| Median gross rent | $1,696 |
| Rent as a share of household income | 21.1% |
| Owner-occupied | 88.1% |
| Vacant homes | 4.2% |
| Median year built | 1974 |
What the homes are
| Detached house | |
|---|---|
| Attached house | |
| 2 to 4 units |
Home values and rents today
Zillow Home Value Index and Zillow Observed Rent Index, courtesy of Zillow. Monthly and current, where the Census figures above are a five-year average and are capped at $2,000,000.
| Typical home value | $468,018as of 2026-07 |
|---|---|
| Typical home value, 1 year | up 1.3% |
| Typical home value, 5 years | up 21% |
| Typical home value, 10 years | up 65.2% |
$170,301 in 2000 to $468,018 in 2026.
Work, commuting and education
American Community Survey 2019–2023 five-year estimates
| Unemployment rate | 7.2% |
|---|---|
| Bachelor's degree or higher | 42.3% |
| High school diploma or higher | 93.1% |
| Works from home | 21.8% |
| Drives to work alone | 68.1% |
| Takes public transport | 4.5% |
| Commutes 45 minutes or more | 40% |
Health
CDC PLACES 2025 release, model-based estimates. These are modelled small-area estimates for adults, not counts of diagnosed cases.
| Obesity | 34.9% 1.5 pts above the national average of 33.4% |
|---|---|
| Diagnosed diabetes | 10.9% 1.1 pts below the national average of 12% |
| Currently smokes | 10.8% 2.4 pts below the national average of 13.2% |
| High blood pressure | 35.5% 1.4 pts above the national average of 34.1% |
| Fair or poor general health | 15.1% 5.2 pts below the national average of 20.3% |
| No health insurance (18–64) | 6.5% 4.8 pts below the national average of 11.3% |
| Depression | 21.7% same as the national average of 21.9% |
| No leisure-time physical activity | 21.1% 4.3 pts below the national average of 25.4% |
| Arthritis | 28.5% 3.4 pts above the national average of 25.1% |
| Binge drinking | 15.4% 0.6 pts below the national average of 16% |
| Taking blood pressure medication | 77.1% 2.4 pts above the national average of 74.7% |
| Cancer (non-skin) | 9.5% 1.8 pts above the national average of 7.7% |
| Current asthma | 10% same as the national average of 10.4% |
| Coronary heart disease | 5.9% same as the national average of 6.2% |
| Routine check-up in past year | 79.4% 2.7 pts above the national average of 76.7% |
| Cholesterol screening | 90.4% 4.5 pts above the national average of 85.9% |
| Cognitive disability | 11.6% 3.2 pts below the national average of 14.8% |
| Colorectal screening | 68.7% 4.4 pts above the national average of 64.3% |
| COPD | 6.1% 0.5 pts below the national average of 6.6% |
| Visited a dentist | 68.5% 7.2 pts above the national average of 61.3% |
| Any disability | 24.6% 6.1 pts below the national average of 30.7% |
| Lacks emotional support | 22.4% 2.4 pts below the national average of 24.8% |
| Food insecurity | 9.3% 7.8 pts below the national average of 17.1% |
| Received food stamps | 6.9% 7.4 pts below the national average of 14.3% |
| Hearing disability | 6.1% 0.6 pts below the national average of 6.7% |
| High cholesterol | 39.1% 2.9 pts above the national average of 36.2% |
| Housing insecurity | 8.8% 5 pts below the national average of 13.8% |
| Independent living disability | 6% 2.4 pts below the national average of 8.4% |
| Lacks transport | 5.4% 3.8 pts below the national average of 9.2% |
| Loneliness | 31.8% 2.6 pts below the national average of 34.4% |
| Mammography use | 77.5% 1.6 pts above the national average of 75.9% |
| Poor mental health (14+ days) | 15.1% 1.7 pts below the national average of 16.8% |
| Mobility disability | 10.7% 3.3 pts below the national average of 14% |
| Poor physical health (14+ days) | 11.6% 1.9 pts below the national average of 13.5% |
| Self-care disability | 2.9% 1.1 pts below the national average of 4% |
| Utility shut-off threat | 5.6% 3.2 pts below the national average of 8.8% |
| Sleeps under 7 hours | 35.9% 0.5 pts below the national average of 36.4% |
| Stroke | 3% same as the national average of 3.4% |
| All natural teeth lost | 9.4% 3.6 pts below the national average of 13% |
| Vision disability | 3.4% 2.2 pts below the national average of 5.6% |
Business and employment
Census ZIP Code Business Patterns 2022
| Business establishments | 55 |
|---|---|
| People employed | 333 |
| Annual payroll | $11,446,000 |
Natural hazard risk
FEMA National Risk Index, estimated for this ZIP code from census tract data — the NRI is not published per ZIP.
| Overall risk | Higher than 12% of US census tracts |
|---|---|
| FEMA rating | Very Low to Relatively Low across the 5 census tracts this ZIP code covers |
| Expected annual loss | 17.6 out of 100 |
| Community resilience | 65.7 out of 100 |
By hazard
Score is out of 100 and is the area-weighted average across the census tracts this ZIP code covers. The rating beside it is the highest any one of those tracts carries.
| Landslide | 89.9Relatively Low at its worst in this ZIP code |
|---|---|
| Drought | 89.4Relatively Moderate at its worst in this ZIP code |
| Winter weather | 71.7Relatively High at its worst in this ZIP code |
| Hurricane | 69.1Relatively Low at its worst in this ZIP code |
| Wildfire | 60.8Relatively Low at its worst in this ZIP code |
| Strong wind | 57.3Relatively Moderate at its worst in this ZIP code |
| Hail | 56.4Relatively Moderate at its worst in this ZIP code |
| Lightning | 55.3Relatively Moderate at its worst in this ZIP code |
| Heat wave | 48.9Relatively Moderate at its worst in this ZIP code |
| Tornado | 40.2Relatively Low at its worst in this ZIP code |
| Earthquake | 31.6Relatively Low at its worst in this ZIP code |
| Cold wave | 26.5Relatively Low at its worst in this ZIP code |
| River flooding | 22.9Relatively Moderate at its worst in this ZIP code |
| Avalanche | 14.9Very Low at its worst in this ZIP code |
| Ice storm | 14Very Low at its worst in this ZIP code |
Compared with Maryland and the United States
State and national columns are figures for those areas, not for this ZIP code. American Community Survey 2019–2023 five-year estimates
| This ZIP | Maryland | United States | |
|---|---|---|---|
| Median household income | $110,694 | $101,652 | $78,538 |
| Income per person | $51,885 | $51,689 | $43,289 |
| Poverty rate | 5.3% | 9.3% | 12.4% |
| Median home value | $388,200 | $397,700 | $303,400 |
| Median gross rent | $1,696 | $1,662 | $1,348 |
| Homeownership | 88.1% | 67.5% | 65% |
| Bachelor's degree or higher | 42.3% | 42.7% | 35% |
| Unemployment rate | 7.2% | 4.9% | 5.2% |
| Works from home | 21.8% | 17.2% | 13.5% |
| Born outside the US | 8.2% | 16.3% | 13.9% |
| Median age | 41.8 | 39.3 | 38.7 |
Climate
NOAA US Climate Normals 1991-2020, from the nearest weather station with a full year of records. The station and its distance are named above, because a station forty kilometres away describes somewhere else.
| Weather station | SHARPSBURG 5 S, MD US8.2 km away |
|---|---|
| Rain in a year | 43 in |
Average high and low by month
| January | 41.2°F / 21.1°F3.13 in rain |
|---|---|
| February | 44.2°F / 23°F2.41 in rain |
| March | 52.5°F / 29°F3.72 in rain |
| April | 64.7°F / 38.6°F3.6 in rain |
| May | 73.5°F / 48.8°F4.57 in rain |
| June | 82°F / 58.2°F4.16 in rain |
| July | 86.1°F / 62.4°F4.28 in rain |
| August | 84.8°F / 60.9°F3.27 in rain |
| September | 78.1°F / 53.7°F4.4 in rain |
| October | 66.8°F / 42°F3.41 in rain |
| November | 55.7°F / 32.1°F3.08 in rain |
| December | 44.8°F / 25.3°F3.46 in rain |
Access to food
USDA Food Access Research Atlas, estimated for this ZIP code from census tract data. Each figure is the share of the ZIP code's land area that falls in a tract carrying that flag.
| Low income and far from a supermarket | None of this ZIP code |
|---|---|
| Far from a supermarket | 42% of this ZIP code's area |
| No vehicle and far from a supermarket | None of this ZIP code |
School districts
NCES Geographic Relationship File 2025, which states the association between each district and each ZIP code tabulation area directly. Elementary and secondary districts can cover the same ground, so shares need not total 100%.
This ZIP code is served by 2 school districts, so the address decides which one, not the ZIP code.
| Frederick County Public Schools | 50.3% of this ZIP code's land area |
|---|---|
| Washington County Public Schools | 49.7% of this ZIP code's land area |
Community and walkability
CDC/ATSDR Social Vulnerability Index 2022 and the EPA National Walkability Index, both estimated for this ZIP code from census tract data. Vulnerability figures are national percentile ranks, not measurements.
| Overall social vulnerability | 12more vulnerable than 12% of US census tracts |
|---|---|
| Socioeconomic status | 20more vulnerable than 20% of US census tracts |
| Household characteristics | 36more vulnerable than 36% of US census tracts |
| Racial and ethnic minority status | 22more vulnerable than 22% of US census tracts |
| Housing type and transport | 10more vulnerable than 10% of US census tracts |
| Walkability | 4 out of 20Least walkable |
Nearby ZIP codes
The closest ZIP codes by centre point, which is not the same as sharing a border.
| 21716 Brunswick, MD | 4.3 km away |
|---|---|
| 21715 Brownsville, MD | 4.4 km away |
| 21718 Burkittsville, MD | 5.3 km away |
| 21755 Jefferson, MD | 9.4 km away |
| 21779 Rohrersville, MD | 10.6 km away |
| 25425 Harpers Ferry, WV | 10.8 km away |
| 21756 Keedysville, MD | 12.6 km away |
| 21777 Point Of Rocks, MD | 12.7 km away |
Location, counties and time zone
County shares from Census 2020 ZCTA relationship files. Time zone from the USDOT National Transportation Atlas, which renders the boundaries written into 49 CFR Part 71.
| Frederick County | 50.3% of this ZIP code's land area |
|---|---|
| Washington County | 49.7% of this ZIP code's land area |
| Time zone | Eastern (UTC-05:00 standard) |
| Daylight saving time | Observed |
| Land area | 32.02 sq mi |
| Water area | 2.83 sq mi |
| Population density | 132 people per sq mi |
| Latitude, longitude | 39.3479, -77.6513 |
Figures are published for this ZIP code or its Census tabulation area unless a section says otherwise. Estimates whose margin of error made them unreliable are omitted rather than shown. Sources: US Census Bureau, CDC, IRS.