ZIP code profile · 2024 county data

ZIP Code 21755

Frederick County, Maryland: Census demographics for this ZIP plus the containing county's FBI UCR crime rate.

Data updated 2026-08-24

379
Property rate /100K (county)
5,706
Population (ZIP)
68
Violent rate /100K (county)

Is ZIP code 21755 safe? Honest data snapshot

ZIP code 21755 sits within Frederick County, MD, a county whose reported crime runs below the national average (see the county-level FBI figures below, not a ZIP-specific calculation).

Reported crime here runs well below the national average: 68 violent incidents and 379 property incidents per 100,000 residents in 2024, per county-level agency submissions.

ZIP 21755 carries a Census-reported population of 5,706, ranking #14 of 28 ZIPs in Frederick County, spread across 34.32 square miles (about 166 people per square mile). For a full breakdown of Frederick County's crime categories and year-over-year trend, see the Frederick County crime page linked below.

ZIP 21755 has no FBI-native crime rate (postal codes are not police jurisdictions). The property-led county proxy above is from Frederick County agency submissions; see methodology for the ZCTA plurality map. Methodology.

ZIP 21755 Census context

These are ZIP/ZCTA demographic estimates, separate from the county-level FBI proxy above. They describe the local settlement, not a crime rate.

Median household income
$129,085
Median age
43.6 years
Owner-occupied homes
88%
Occupied homes
2,024

Source: U.S. Census Bureau, ACS 2022 5-year ZCTA estimates (income, age, and occupied housing tenure).

How useful is the county proxy for ZIP 21755?

Within the participating-agency records for Frederick County, reported violent and property crime rates both sit below their U.S. benchmarks: violent crime is 81% below and property crime is 78% below. The two submitted measures point in the same direction, but they do not establish complete county coverage or turn the result into a ZIP-level rating for 21755. Both comparisons use the same 2024 county reporting population and FBI-submitted counts, so the two directions are internally comparable for this release, not evidence about a different year.

21755 is comparatively spread out at about 166 people per square mile. That settlement pattern may differ sharply from the county's population centers, another reason to use the county rates as regional context rather than a local estimate.

Frederick County UCR book ZIP 21755 inherits

ZIP 21755 itself is about 166 people per Census sq mi across 34.3 sq mi (5,706 residents), a postal settlement fact independent of the county UCR proxy.

ZIP 21755 accounts for roughly 2.1% of the county reporting population (5,706 of 271,717).

Frederick County's 2024 UCR book concentrates in larceny-theft (70% of 1,213 offenses; mix index 5,103). ZIP 21755 inherits that county mix, not a postal-native split.

Frederick County 2024 vs 2023: violent counts -16% vs 2023; property counts -23% vs 2023. Year-over-year moves are county agency submissions, still not ZIP-native.

Frederick County offense mix (2024)

Mix index is HHI × 10,000 on county offense-type shares. Distinct from the per-100K rates in the hero; still county-agency data, not a ZIP-native FBI table.

Nationwide peers for ZIP 21755

Similar county violent rate (~68/100K)

Similar Census population (~5,706)

County detail: Frederick County · State atlas: Maryland

Sources: U.S. Census Bureau (ZIP population, land area, 2020 ZCTA-to-county relationship file, ACS 5-year estimates) and FBI Uniform Crime Reporting (UCR) Program, Crime in the United States (CIUS) Table 10 (county-level crime, attributed via ZIP-to-county crosswalk).

Verify with Census.gov Geography and FBI.gov UCR.

Read our methodology , how this data is sourced, computed, and verified.

Every figure on PlainCrime is rendered directly from FBI Uniform Crime Reporting (UCR) source data, no number is typed in by an editor. This page combines Census ZIP-level figures with a ZIP-to-county crosswalk to attribute FBI UCR crime data honestly, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.