21788 ZIP Code — Thurmont, MD

Frederick County, Maryland

ZIP code 21788 is located in Thurmont, Maryland, within Frederick County. It covers approximately 65.44 square miles and serves a population of 11,412 residents. This is a standard ZIP code in the Eastern (ET) timezone, served by area code 240/301.

About ZIP code 21788

The housing stock consists of predominantly single-family detached homes. Most homes were built in the 1990s, giving the area an established character. Median home value is $328,600. Owner-occupancy is high at 81%, well above the national average.

The gap between median ($90,091) and mean household income suggests income inequality — a small number of higher earners pull the average up. 35% of households receive Social Security income, suggesting a notable retiree or disability population.

The dominant occupation class is management, business, and professional, with education and healthcare as the leading industry. The average commute of 29 minutes is near the national average.

Educational attainment is near the national average, with 28% of residents holding a bachelor's degree or higher.

Overall, ZIP code 21788 reflects a community defined by high homeownership and a significant Social Security-dependent population.

11,412

population

65.44

sq mi land

Standard

ZIP type

Eastern (ET)

timezone

21788 ZIP code map

Cities in ZIP code 21788

Below are the cities the US Postal Service accepts for ZIP code 21788. Using any city not on this list may result in mail delivery delays.

City	Status
Thurmont	Acceptable
Thurmont	Preferred

Nearby ZIP codes

21778 Rocky Ridge (4.9 mi) 21780 Sabillasville (6 mi) 21702 Frederick (7 mi) 21727 Emmitsburg (7.2 mi) 21798 Woodsboro (7.8 mi) 21773 Myersville (8.1 mi) 21793 Walkersville (8.2 mi) 21719 Cascade (8.4 mi) 21783 Smithsburg (8.8 mi) 21757 Keymar (9.4 mi) 21701 Frederick (10.1 mi) 17214 Blue Ridge Summit (10.3 mi)

Demographics updated 05/2026

Population
Total population	11,412
Population density	174 / sq mi
State FIPS	24
County FIPS	021

Geography
Land area	65.44 sq mi
Water area	0.51 sq mi
Latitude	39.5949
Longitude	-77.4239
Timezone	Eastern (ET)
Area code	240/301

Total population by age

Gender

Race & ethnicity

Economics updated 05/2026

Household income

Income range	This ZIP	County avg	State avg
Under $50k	28.3%	22.0%	28.2%
$50k – $100k	30.7%	27.2%	28.2%
$100k – $200k	28.2%	36.5%	30.1%
Over $200k	12.8%	14.3%	13.4%

Demographics & statistics

11,412

Population

174

People per sq mi

47.9

Median age

$90,091

Median household income

$49,567

Per capita income

$328,600

Median home value

$1,025

Median monthly rent

80.8%

Home ownership

8.2%

Poverty rate

2.4%

Unemployment

4,061

Housing units

27.7%

Bachelor's or higher

Age distribution

Male Female

166

Under 5

163

227

5–9

222

384

10–14

377

327

15–19

320

361

20–24

355

701

25–34

687

514

35–44

504

880

45–54

863

600

55–59

588

478

60–64

469

682

65–74

669

248

75–84

243

194

85+

190

← Male

Female →

Age summary

Group	Count	%
Under 18	1,997	17.5%
18 and over	9,415	82.5%
65 and over	2,226	19.5%
Median age	47.9 years

Race & ethnicity

White 91.3%

Two or more races 3.4%

Hispanic or Latino 2.7%

Other race 1.2%

Black or African American 0.9%

Asian 0.4%

American Indian / Alaska Native 0.1%

Group	Count	%
White	10,710	91.3%
Two or more races	395	3.4%
Hispanic or Latino	317	2.7%
Other race	141	1.2%
Black or African American	100	0.9%
Asian	51	0.4%
American Indian / Alaska Native	15	0.1%

Household income

Income range	This ZIP	County avg	State avg
Under $50k	28.3%	22.0%	28.2%
$50k – $100k	30.7%	27.2%	28.2%
$100k – $200k	28.2%	36.5%	30.1%
Over $200k	12.8%	14.3%	13.4%

Under $10k 1.5%

$10k–$15k 3.6%

$15k–$25k 7.2%

$25k–$35k 4.5%

$35k–$50k 8.4%

$50k–$75k 13.1%

$75k–$100k 18.0%

$100k–$150k 18.1%

$150k–$200k 9.6%

$200k+ 16.0%

Range	% of households
Under $10k	1.5%
$10k–$15k	3.6%
$15k–$25k	7.2%
$25k–$35k	4.5%
$35k–$50k	8.4%
$50k–$75k	13.1%
$75k–$100k	18.0%
$100k–$150k	18.1%
$150k–$200k	9.6%
$200k+	16.0%
Median income	$90,091

Housing

Home values

Under $50k 1.7%

$50k–$100k 2.1%

$100k–$150k 0.9%

$150k–$200k 9.7%

$200k–$300k 28.2%

$300k–$500k 48.7%

$500k–$1M 7.2%

$1M+ 1.5%

Housing overview

Metric	Value
Median home value	$328,600
Median rent / month	$1,025
Owner occupied	80.8%
Renter occupied	19.2%
Vacant	6.2%
Single-family detached	79.0%
Large apartment buildings	2.1%
Mobile homes	1.0%
Median rooms	6.7
Avg household size (owned)	2.50

Year built

Era	%
2020 or later	0.0%
2010–2019	5.0%
2000–2009	11.0%
1990–1999	17.9%
1980–1989	11.3%
1970–1979	12.0%
1960–1969	10.2%
1950–1959	10.3%
1940–1949	4.7%
1939 or earlier	17.5%

Bedrooms

Size	% of units
No bedroom (studio)	1.0%
1 bedroom	7.4%
2 bedrooms	15.8%
3 bedrooms	45.8%
4 bedrooms	25.4%
5+ bedrooms	4.7%

Vehicles per household

Vehicles	% of households
No vehicle	2.0%
1 vehicle	24.9%
2 vehicles	32.2%
3 or more	41.0%

Heating fuel

Fuel type	%
Utility gas	4.0%
Electricity	54.8%
Propane / LP gas	6.8%
Fuel oil	24.2%
Wood	4.5%
Solar	0.2%
No fuel used	0.9%

Households & families

Household type	Count	%
Married-couple family	2,718	58.5%
Cohabiting couple	362	7.8%
Male householder, no spouse	555	11.9%
Female householder, no spouse	1,013	21.8%
Households with children under 18	1,223	26.3%
Households with seniors (65+)	1,687	36.3%
Average household size	2.45

Marital status

Status	Male	Female
Never married	30.2%	20.0%
Married	57.8%	56.5%
Separated	0.7%	1.9%
Widowed	1.8%	10.3%
Divorced	9.5%	11.3%

Education

Less than 9th grade 2.9%

Some HS, no diploma 6.3%

HS graduate 35.8%

Some college, no degree 17.7%

Associate's degree 9.7%

Bachelor's degree 15.7%

Graduate / professional 12.0%

Metric	%
HS diploma or higher	90.8%
Bachelor's or higher	27.7%

School enrollment (ages 3–17)

Type	Count	%
Nursery / preschool	88	3.7%
Kindergarten	56	2.4%
Elementary school	1,002	42.3%
High school	637	26.9%
College / grad school	586	24.7%

Employment

Industry of employment

Education & healthcare 24.1%

Professional & management 13.0%

Construction 12.0%

Retail trade 10.1%

Public administration 8.8%

Other services 6.6%

Arts, food & hospitality 6.3%

Finance & real estate 5.9%

Manufacturing 5.6%

Information 2.3%

Transportation & utilities 2.1%

Agriculture & mining 1.9%

Wholesale trade 1.2%

Occupation

Category	%
Management, business & arts	40.5%
Service	16.0%
Sales & office	20.1%
Natural resources & construction	12.8%
Production & transportation	10.6%

Employment type

Type	%
Private sector	69.9%
Government	23.8%
Self-employed	6.1%
Unpaid family workers	0.2%

Commute

Method	%
Drive alone	77.8%
Carpool	7.8%
Public transit	0.2%
Walk	2.0%
Work from home	11.0%
Other means	1.2%
Avg commute (minutes)	29.3

Poverty

All people 8.2%

Under 18 years 14.9%

18 and over 6.8%

Married-couple families 3.4%

Female-led households 20.3%

Income support

Source	% of households
Social Security	35.1%
Retirement income	27.0%
Supplemental Security	3.3%
Cash public assistance	2.0%
Food stamps / SNAP	9.2%

Health indicators

Condition	%
Obesity	32.8%
High blood pressure	33.3%
High cholesterol	36.4%
Diabetes	10.3%
Heart disease	6.1%
Stroke	2.8%
Asthma	9.9%
Arthritis	25.0%
Kidney disease	2.7%
Pulmonary disease	6.5%
Cancer	7.2%

Behavior / access	%
Smoking	15.1%
Binge drinking	16.4%
No physical activity	21.3%
Less than 7 hrs sleep	31.5%
Depression	20.9%
Fair or poor health	11.7%
Poor mental health	14.3%
Poor physical health	8.8%
No health insurance	9.7%
Visited doctor (checkup)	75.3%
Visited dentist	67.1%
Cholesterol screening	92.0%
Teeth loss	10.4%

Veterans & disability

Veterans	Count	%
Civilian veterans	742	7.9%

Disability	%
Any disability	12.2%
Under 18	2.9%
18–64 years	9.5%
65 and over	29.3%

Health insurance coverage

Type	%
Private insurance	79.0%
Public insurance	33.2%
No insurance	5.0%
Uninsured under 19	6.7%

Language & origin

Language spoken at home (age 5+)

Language	Count	%
English only	11,083	97.1%
Spanish	88	0.8%
Other Indo-European	88	0.8%
Asian & Pacific Islander	0	0.0%
Other languages	0	0.0%

Place of birth & citizenship

Origin	Count	%
Native born (US)	11,225	98.4%
Born in same state	11,032	96.7%
Born in different state	7,255	63.6%
Foreign born	193	1.7%
Naturalized citizen	187	1.6%
Not a US citizen	117	62.6%

Ancestry

Ancestry	Count	%
French	1,532	13.4%
Italian	1,480	13%
Arab	806	7.1%
English	139	1.2%

Ancestry	Count	%
Irish	54	0.5%
Dutch	45	0.4%
Polish	33	0.3%
German	13	0.1%

Technology access

Metric	% of households
Computer access	40.7%
Internet access	91.1%

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

Frequently asked questions about ZIP code 21788

What city is ZIP code 21788 in?

ZIP code 21788 is primarily assigned to Thurmont, Maryland.

What county is ZIP code 21788 in?

ZIP code 21788 falls within Frederick County, Maryland.

Is ZIP code 21788 mostly owner-occupied?

81% of occupied units in ZIP code 21788 are owner-occupied, well above the national average.

Does ZIP code 21788 have a large retiree population?

35% of households in ZIP code 21788 receive Social Security income, suggesting a significant retiree or disability population.

What is the typical home value in ZIP code 21788?

The median home value in ZIP code 21788 is $328,600.

What is the population of ZIP code 21788?

ZIP code 21788 has an estimated population of 11,412 residents, with a density of 174 people per square mile.

What timezone is ZIP code 21788 in?

ZIP code 21788 observes the EST timezone.