21664 ZIP Code — Secretary, MD

Dorchester County, Maryland

ZIP code 21664 is located in Secretary, Maryland, within Dorchester County. It covers approximately 0.29 square miles and serves a population of 642 residents. This is a standard ZIP code in the Eastern (ET) timezone, served by area code 410/443.

About ZIP code 21664

The housing stock consists of predominantly single-family detached homes. Most homes were built in the pre-1940, giving the area an established character. Median home value is $162,500. Owner-occupancy sits near the national average at 62%.

Median household income is $66,458. SNAP benefit usage at 25% of households reflects economic stress in the area.

The dominant occupation class is service, with professional and management as the leading industry. The average commute of 28 minutes is near the national average.

College attainment at 14% is below the national average, consistent with a trades and production-oriented local economy.

Overall, ZIP code 21664 reflects a community defined by a trades-oriented workforce and elevated reliance on food assistance.

642

population

0.29

sq mi land

Standard

ZIP type

Eastern (ET)

timezone

21664 ZIP code map

Cities in ZIP code 21664

Below are the cities the US Postal Service accepts for ZIP code 21664. Using any city not on this list may result in mail delivery delays.

City	Status
Secretary	Acceptable

Demographics updated 05/2026

Population
Total population	642
Population density	2,214 / sq mi
State FIPS	24
County FIPS	019

Geography
Land area	0.29 sq mi
Water area	0.02 sq mi
Latitude	38.6084
Longitude	-75.9476
Timezone	Eastern (ET)
Area code	410/443

Total population by age

Gender

Race & ethnicity

Economics updated 05/2026

Household income

Income range	This ZIP	County avg	State avg
Under $50k	53.0%	48.7%	28.2%
$50k – $100k	20.9%	30.4%	28.2%
$100k – $200k	24.7%	17.3%	30.1%
Over $200k	1.4%	3.7%	13.4%

Demographics & statistics

642

Population

2,214

People per sq mi

32.8

Median age

$66,458

Median household income

$25,755

Per capita income

$162,500

Median home value

$1,183

Median monthly rent

61.7%

Home ownership

9.8%

Poverty rate

7.6%

Unemployment

164

Housing units

14.1%

Bachelor's or higher

Age distribution

Male Female

Under 5

5–9

10–14

15–19

20–24

25–34

35–44

45–54

55–59

60–64

65–74

75–84

85+

← Male

Female →

Age summary

Group	Count	%
Under 18	221	34.4%
18 and over	421	65.6%
65 and over	63	9.8%
Median age	32.8 years

Race & ethnicity

White 62.4%

Hispanic or Latino 18.1%

Other race 15.2%

Two or more races 4.2%

Black or African American 0.1%

Group	Count	%
White	489	62.4%
Hispanic or Latino	142	18.1%
Other race	119	15.2%
Two or more races	33	4.2%
Black or African American	1	0.1%

Household income

Income range	This ZIP	County avg	State avg
Under $50k	53.0%	48.7%	28.2%
$50k – $100k	20.9%	30.4%	28.2%
$100k – $200k	24.7%	17.3%	30.1%
Over $200k	1.4%	3.7%	13.4%

Under $10k 1.4%

$10k–$15k 4.2%

$15k–$25k 9.8%

$25k–$35k 4.2%

$35k–$50k 21.0%

$50k–$75k 15.0%

$75k–$100k 14.0%

$100k–$150k 22.9%

$150k–$200k 7.5%

Range	% of households
Under $10k	1.4%
$10k–$15k	4.2%
$15k–$25k	9.8%
$25k–$35k	4.2%
$35k–$50k	21.0%
$50k–$75k	15.0%
$75k–$100k	14.0%
$100k–$150k	22.9%
$150k–$200k	7.5%
Median income	$66,458

Housing

Home values

Under $50k 6.8%

$50k–$100k 15.2%

$100k–$150k 18.2%

$150k–$200k 27.3%

$200k–$300k 23.5%

$300k–$500k 9.1%

Housing overview

Metric	Value
Median home value	$162,500
Median rent / month	$1,183
Owner occupied	61.7%
Renter occupied	38.3%
Vacant	13.0%
Single-family detached	94.7%
Large apartment buildings	0.0%
Mobile homes	0.8%
Median rooms	5.4
Avg household size (owned)	2.32

Year built

Era	%
2020 or later	0.0%
2010–2019	1.2%
2000–2009	2.0%
1990–1999	1.2%
1980–1989	24.4%
1970–1979	21.1%
1960–1969	1.6%
1950–1959	8.9%
1940–1949	3.7%
1939 or earlier	35.8%

Bedrooms

Size	% of units
No bedroom (studio)	0.0%
1 bedroom	5.3%
2 bedrooms	25.2%
3 bedrooms	63.8%
4 bedrooms	4.5%
5+ bedrooms	1.2%

Vehicles per household

Vehicles	% of households
No vehicle	1.4%
1 vehicle	36.4%
2 vehicles	28.5%
3 or more	33.6%

Heating fuel

Fuel type	%
Electricity	75.7%
Propane / LP gas	5.6%
Fuel oil	10.7%
Wood	5.1%

Households & families

Household type	Count	%
Married-couple family	93	43.5%
Cohabiting couple	24	11.2%
Male householder, no spouse	41	19.2%
Female householder, no spouse	56	26.2%
Households with children under 18	98	45.8%
Households with seniors (65+)	51	23.8%
Average household size	3.00

Marital status

Status	Male	Female
Never married	46.5%	28.3%
Married	43.9%	38.6%
Separated	1.3%	6.3%
Widowed	3.9%	6.7%
Divorced	4.3%	20.2%

Education

Less than 9th grade 1.3%

Some HS, no diploma 7.3%

HS graduate 58.2%

Some college, no degree 11.2%

Associate's degree 7.8%

Bachelor's degree 8.1%

Graduate / professional 6.0%

Metric	%
HS diploma or higher	91.4%
Bachelor's or higher	14.1%

School enrollment (ages 3–17)

Type	Count	%
Nursery / preschool	2	0.9%
Kindergarten	4	1.9%
Elementary school	129	59.7%
High school	68	31.5%
College / grad school	13	6.0%

Employment

Industry of employment

Professional & management 18.3%

Education & healthcare 17.3%

Arts, food & hospitality 14.7%

Construction 9.2%

Transportation & utilities 8.2%

Retail trade 6.2%

Public administration 5.9%

Agriculture & mining 4.6%

Other services 4.6%

Information 3.9%

Finance & real estate 3.9%

Manufacturing 3.3%

Occupation

Category	%
Management, business & arts	24.8%
Service	32.0%
Sales & office	16.0%
Natural resources & construction	10.8%
Production & transportation	16.3%

Employment type

Type	%
Private sector	77.5%
Government	10.5%
Self-employed	12.1%
Unpaid family workers	0.0%

Commute

Method	%
Drive alone	90.1%
Carpool	5.6%
Public transit	0.0%
Walk	0.0%
Work from home	4.3%
Other means	0.0%
Avg commute (minutes)	27.8

Poverty

All people 9.8%

Under 18 years 11.8%

18 and over 8.8%

Married-couple families 0.0%

Female-led households 26.8%

Income support

Source	% of households
Social Security	29.4%
Retirement income	27.1%
Supplemental Security	0.0%
Cash public assistance	7.0%
Food stamps / SNAP	25.2%

Health indicators

Condition	%
Obesity	36.3%
High blood pressure	36.8%
High cholesterol	34.3%
Diabetes	11.2%
Heart disease	6.6%
Stroke	3.2%
Asthma	9.9%
Arthritis	27.7%
Kidney disease	3.0%
Pulmonary disease	7.3%
Cancer	7.7%

Behavior / access	%
Smoking	17.0%
Binge drinking	15.2%
No physical activity	24.0%
Less than 7 hrs sleep	31.7%
Depression	20.1%
Fair or poor health	13.6%
Poor mental health	14.0%
Poor physical health	9.5%
No health insurance	11.0%
Visited doctor (checkup)	79.0%
Visited dentist	63.8%
Cholesterol screening	92.1%
Teeth loss	11.7%

Veterans & disability

Veterans	Count	%
Civilian veterans	23	5.5%

Disability	%
Any disability	16.8%
Under 18	16.3%
18–64 years	12.3%
65 and over	44.4%

Health insurance coverage

Type	%
Private insurance	54.8%
Public insurance	51.6%
No insurance	10.9%
Uninsured under 19	5.3%

Language & origin

Language spoken at home (age 5+)

Language	Count	%
English only	620	96.6%
Spanish	49	7.9%
Other Indo-European	49	7.9%
Asian & Pacific Islander	0	0.0%
Other languages	0	0.0%

Place of birth & citizenship

Origin	Count	%
Native born (US)	560	87.2%
Born in same state	548	85.4%
Born in different state	379	59.0%
Foreign born	12	1.9%
Naturalized citizen	82	12.8%
Not a US citizen	25	30.5%

Ancestry

Ancestry	Count	%
Arab	177	27.6%
Italian	44	6.9%

Ancestry	Count	%
French	42	6.5%
English	2	0.3%

Technology access

Metric	% of households
Computer access	33.3%
Internet access	95.3%

Source: U.S. Census Bureau, American Community Survey 2025 estimates.

Frequently asked questions about ZIP code 21664

What city is ZIP code 21664 in?

ZIP code 21664 is primarily assigned to Secretary, Maryland.

What county is ZIP code 21664 in?

ZIP code 21664 falls within Dorchester County, Maryland.

Is ZIP code 21664 family-oriented?

34% of residents in ZIP code 21664 are under 18, reflecting a younger, family-oriented community.

How educated is the population of ZIP code 21664?

14% of residents hold a bachelor's degree or higher — below the national average of ~33%, consistent with a trades-oriented local economy.

What is the typical home value in ZIP code 21664?

The median home value in ZIP code 21664 is $162,500.

What is the population of ZIP code 21664?

ZIP code 21664 has an estimated population of 642 residents, with a density of 2,206 people per square mile.

What timezone is ZIP code 21664 in?

ZIP code 21664 observes the EST timezone.