ZIP code profile · 2024 county data

ZIP Code 21639

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

Data updated 2026-08-24

403
Property rate /100K (county)
4,734
Population (ZIP)
81
Violent rate /100K (county)

Is ZIP code 21639 safe? Honest data snapshot

ZIP code 21639 sits within Caroline County, MD. The figures below are the county's own FBI UCR numbers for 2024, the most accurate available statistic for this location, not a ZIP-specific calculation.

Caroline County reported a violent-crime rate of 81 per 100,000 residents and a property-crime rate of 403 per 100,000 in 2024, drawing on county-level agency submissions.

Based on just 27 reported violent incidents across a county population of 33,293, this count is too low to support a reliable per-100K rate comparison. It may reflect a genuinely low-crime county, or it may reflect incomplete agency-level reporting to the FBI UCR Program for this county and year, small county-level counts are common in FBI Table 10 and should be treated as a data point, not a precise safety ranking.

ZIP 21639 carries a Census-reported population of 4,734, ranking #4 of 8 ZIPs in Caroline County, spread across 33.09 square miles (about 143 people per square mile). For a full breakdown of Caroline County's crime categories and year-over-year trend, see the Caroline County crime page linked below.

ZIP 21639 has no FBI-native crime rate (postal codes are not police jurisdictions). The property-led county proxy above is from Caroline County agency submissions; see methodology for the ZCTA plurality map. Methodology.

ZIP 21639 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
$56,173
Median age
35.4 years
Owner-occupied homes
70%
Occupied homes
1,711

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

Caroline County UCR book ZIP 21639 inherits

ZIP 21639 itself is about 143 people per Census sq mi across 33.1 sq mi (4,734 residents), a postal settlement fact independent of the county UCR proxy.

ZIP 21639 accounts for roughly 14.2% of the county reporting population (4,734 of 33,293).

Caroline County leans on larceny-theft at 50% of reported offenses (mix index 3,433). ZIP 21639 has no separate FBI offense book.

Caroline County 2024 vs 2023: property counts -15% vs 2023. Year-over-year moves are county agency submissions, still not ZIP-native.

Caroline 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 21639

Similar county violent rate (~81/100K)

Similar Census population (~4,734)

County detail: Caroline 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.