Residential delivery area · Maryland
ZIP Code 21788: Thurmont, MD
ZIP code 21788 uses the postal name Thurmont, Maryland and lies entirely in Frederick County (Census 2020 ZIP-county file). About 12,000 people live there (Census Bureau, ACS 2020-2024). Median household income is $98,856 (Census Bureau, ACS 2020-2024). By Census place, its land lies in Thurmont (5%), Lewistown (1%) and Graceham (under 1%); 94% is outside any Census place.
- ACS2020-24
- Census2020
- FHFA2025
- ZBP2023
- IRS2022
- Town
- Thurmont · its only residential ZIP
- County
- Frederick County
- Census places
- Thurmont (5%); Lewistown (1%) census-designated place; Graceham (under 1%) census-designated place
- Neighborhoods
- Altogether, Catoctin Heights, Catoctin Highlands, Colonial Heights, Gateway, Thurmont West GeoNames
- Metro area
- Washington-Arlington-Alexandria, DC-VA-MD-WV
- House district
- MD-6 119th Congress
- State
- Maryland
- Time zone
- Eastern
- Land area
- 65.4 sq mi · 178 people per sq mi
Where is ZIP code 21788?
21788 centers on 39.590°, -77.414° and covers 65.4 square miles of land plus 0.5 of water. It borders 9 ZIP codes: 21778, 21780, 21798, 21702, 21793, 21773, 21727, 21783, 21701.
The map draws ZIP code areas only. For the streets inside 21788, open its center on OpenStreetMap.
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries and the 2023 Gazetteer (2020 ZCTAs); ZIP-to-county shares, Census places and House districts (119th Congress) from the Census 2020 relationship files (shares of land); metro area from the OMB delineation (July 2023); town name and time zone from simplemaps US ZIP Codes (CC BY 4.0); neighborhoods from the GeoNames gazetteer (CC BY 4.0), placed in this ZIP code by PlainZIP.
How does 21788 compare with the rest of Frederick County?
| Measure | 21788 | In Frederick County | In MD |
|---|---|---|---|
| People (ACS 2020-2024) | 11,654 | 9th of 35 | 170th of 477 |
| Median household income | $99k | 22nd of 26 | 173rd of 293 |
| Median home value | $379k | 23rd of 28 | 202nd of 320 |
Its median household income is higher than in 80% of U.S. residential ZIP codes, and it is denser than 61% of all U.S. residential ZIP codes. ZIP codes at the ACS caps ($250,000 or more for household income, $2,000,000 or more for home value) share the top rank.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B19013, B25077); ranks by PlainZIP over residential ZIP codes (ZCTAs).
How many people live in 21788?
The 2020 Census counted 11,491 people in 21788; the ACS, which samples households over 2020-2024, estimates 11,654. Between the 2010 and 2020 censuses its population fell 1.1% (its boundary stayed at least 90% the same).
- People, ACS 2020-2024
- 11,654
- 2020 Census count
- 11,491−1.1% since 2010 (11,622)
- Households
- 4,649
- Median age
- 44.6
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B01002, B11001); 2020 Census (DHC P1); 2010 Census (SF1 P1).
Who lives in 21788?
Of the 11,654 people the ACS estimates in 21788, 19.4% are under 18 and 20.1% are 65 or older. The largest group by race and Hispanic origin is White (not Hispanic) (89.7%).
- Under 1819.4%
- 18 to 6460.5%
- 65 and older20.1%
- White, not Hispanic89.7%
- Hispanic or Latino5.4%
- Other or two or more2.7%
- Asian, not Hispanic1.4%
- Black, not Hispanic0.9%
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01001 age by sex, B03002 Hispanic or Latino origin by race); shares of the estimated population, small ZIP codes carry wide margins.
What do households in 21788 earn?
Median household income is $98,856 (ACS 2020-2024), the 22nd highest of the 26 ranked ZIP codes in Frederick County. It is not measurably different from 2015-2019 ($94,156 in 2024 dollars): the change is within the surveys' margins of error.
- Median household income
- $98,856
- Income per person
- $52,036
- Below the poverty line
- 8.6%
- Unemployed (of the labor force)
- 2.8%
- Adults 25+ with a bachelor's degree
- 31.3%
- Adjusted gross income per tax return, 2022
- $79,3116,060 returns; wages 71% of AGI (IRS)
Source: U.S. Census Bureau, ACS 2020-2024 and 2015-2019 5-year estimates (B19013, B19301, B17001, B23025, B15003; 2015-2019 dollars converted with the BLS CPI-U, 1.22699); IRS Statistics of Income, ZIP code data, tax year 2022 (adjusted gross income per return, filed under the address on the return).
What are homes worth in 21788?
FHFA's house price index for 21788, built from repeat sales and appraisals of the same homes, rose 62% from 2015 to 2025 and rose 38% from 2020 to 2025, and moved −0.9% in 2025.
- Median home value (owners' estimate)
- $379,200
- Median gross rent
- $959
- Homes owned by their occupants
- 82.1%
- Housing units
- 4,871
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B25077, B25064, B25003, B25001); FHFA House Price Index, annual five-digit ZIP, updated 2026-03-31.
What businesses are in 21788?
216 business establishments had a location in this ZIP code in 2023, 5 fewer than in 2018; the most are in construction (ZIP Code Business Patterns).
- Construction44
- Retail trade36
- Other services (except public administration)28
- Accommodation and food services20
- Administrative and support and waste management and remediation services17
- Professional, scientific, and technical services13
Source: U.S. Census Bureau, ZIP Code Business Patterns 2023 and 2018 (establishments with paid employees, by the business's ZIP code).
Which ZIP codes are next to 21788?
| ZIP | Town | People | Household income | Distance |
|---|---|---|---|---|
| 21778 | Rocky Ridge | 745 | $77k | 4.9 mi |
| 21780 | Sabillasville | 2,159 | $84k | 6.5 mi |
| 21798 | Woodsboro | 2,928 | $117k | 7.3 mi |
| 21702 | Frederick | 49,605 | $107k | 7.8 mi |
| 21793 | Walkersville | 10,719 | $122k | 7.9 mi |
| 21773 | Myersville | 5,826 | $162k | 8.0 mi |
| 21727 | Emmitsburg | 6,052 | $95k | 8.2 mi |
| 21783 | Smithsburg | 9,910 | $101k | 8.5 mi |
| 21701 | Frederick | 43,048 | $107k | 11.0 mi |
| 21757 | Keymar | 2,671 | $101k | 8.3 mi (near) |
Source: PlainZIP from the Census 2020 ZCTA boundaries (shared edges) and internal points; figures ACS 2020-2024.