What city is ZIP code 21631?

ZIP code 21631 is in Secretary, MD (Dorchester County).

What county is ZIP code 21631 in?

ZIP code 21631 is mostly in Dorchester County, Maryland.

How many people live in ZIP code 21631?

About 2,429 people live in the 21631 ZIP Code Tabulation Area, based on American Community Survey 5-year estimates.

Checked Oct 26, 2026

ZIP Code 21631

Secretary, MD, Dorchester County

Population

2,429

Land area

24.1sq mi

People per sq mi

101

City

Secretary

ZIP 21631 and nearby ZIP codes

Full map

ZIP 21631 at a glance

ZIP 21631 (Secretary) is 84% less dense than Maryland as a whole.
Households here earn a median of $73,864 a year, 29% less than the Maryland figure of $103,678.
A typical owner-occupied home is valued at $306,700 (27% below Maryland) and median rent is $1,541 a month.

Local data for ZIP 21631

Counts from official public data

Housing and community stats

ZIP 21631, American Community Survey 2020-2024

Full profile

Median household income

$73,864

Poverty rate

4.9%

Median home value

$306,700

Median rent

$1,541/mo

Homeownership

85.4%

Bachelor's or higher

23.8%

Median age

48.3

Average commute

18.4 min

Income, education and commute

Economy and federal money

Businesses, pandemic loans and political donations

Details

Business establishments

ZIP Business Patterns 2023

Employees

290

$12.8M annual payroll

PPP loans

$3.8M

107 loans

Campaign donations

$801

25% D, 72% R, 2026 cycle

PPP loans in this ZIP

Environment and hazard risk

ZIP 21631, from FEMA, NOAA and EPA

Full report

Natural hazard risk

Relatively Low

Top: coastal flooding

Storm events since 1996

430

Countywide, mostly thunderstorm wind

Flood insurance policies

1,382

8.8% of homes, county

July high / Jan low

90° / 28°F

Hazards, floods and storm history Check a flood zone

Health statistics

Share of adults in ZIP 21631, CDC PLACES estimates

All 40 measures

Obesity

37.5%

U.S. 33.3% +4.2 pts

Diabetes

14.0%

U.S. 12.1% +1.9 pts

Smoking

14.1%

U.S. 12.8% +1.3 pts

Uninsured (18-64)

8.2%

U.S. 11.1% -2.9 pts

Frequently asked questions

What city is ZIP code 21631?: ZIP code 21631 is in Secretary, MD (Dorchester County).
What county is ZIP code 21631 in?: ZIP code 21631 is mostly in Dorchester County, Maryland.
How many people live in ZIP code 21631?: About 2,429 people live in the 21631 ZIP Code Tabulation Area, based on American Community Survey 5-year estimates.

Source: U.S. Census Bureau (ZIP Code Tabulation Areas, American Community Survey) · Data as of 12/31/2023. ZIP Code Tabulation Areas closely match, but are not identical to, USPS ZIP code delivery areas.