Photo: Acroterion · CC BY-SA 4.0Living in Mount Airy, MD: what to set up and who to call
All of Mount Airy gets its mail under one ZIP code, 21771. For home internet, most of Mount Airy can choose between Xfinity and Verizon.
I’m new in town
What to set up in Mount Airy, and who provides it. Tap an answer for the details and where they come from.
Power, water and internet
Who to call to start service at a new address in Mount Airy.
Power comes from Potomac Edison
Potomac Edison (The Potomac Edison Co.), an investor-owned utility, serves all of Mount Airy. Its homes paid an average of 15.4¢ per kWh in 2025, about $172 a month (its average across Maryland, for customers on its standard service). Maryland lets you buy power from another supplier; 2% of Potomac Edison’s home customers do, and Potomac Edison still delivers it.
Service territory: HIFLD Electric Retail Service Territories (map dated Aug 2023). Prices and customers: EIA-861, 2025.
Water comes from Town of Mount Airy water system
The Town of Mount Airy water system supplies almost all of Mount Airy. It draws ground water and serves 9,890 people in all.
No health-based violations reported to EPA in the five years to October 2026, like 80% of the 5,012 systems serving 3,301–10,000 people.
The latest lead result on file, the 90th percentile of homes sampled in Jan 2022–Dec 2024, was 1.4 ppb, below the 15 ppb action level that applied. That’s higher than 58% of similar systems’ latest results.
The system’s full record: EPA ECHO report
EPA SDWIS via Envirofacts (violations pulled Oct 9, 2026) and ECHO (lead samples, 2026Q3); service area: EPA Community Water System Service Area Boundaries v3.0. Violations are counted by the start of their compliance period. MD0060007.
4 home internet providers serve Mount Airy
100% of 3,396 addresses can get 100/20 Mbps; 3% can get fiber.
| Provider | Technology | Addresses | Fastest (Mbps) |
|---|---|---|---|
| Xfinity | Cable, Fiber | 100% | 2,000/250 |
| Verizon | Fixed wireless, Fiber | 81% | 300/20 |
| AT&T | Fixed wireless | 40% | 25/3 |
| T-Mobile | Fixed wireless | 19% | 25/3 |
FCC National Broadband Map, as of December 2025. Availability as providers report it, not speeds people get.
We don’t have Mount Airy’s trash rules yet
Pickup rules, the dump and recycling in Mount Airy.
Where your child goes to school
Public school districts and the school path by grade.
Most of Mount Airy (66%) is in Carroll County Public Schools; parts are in Frederick County Public Schools (34%).
A−School gradeSee Schools →U.S. Department of Education, NCES Common Core of Data, 2024–25. Enrollment rules and registration are the district’s.
Town hall and registering to vote
Who to call, and how to register.
Election office: FVAP local election office directory, updated Aug 2025; jurisdictions: EAC EAVS 2024. Registration rules and links: vote.gov, updated Mar 11, 2026.
Mount Airy is in ZIP code 21771
ZIP codes where Mount Airy residents live, with the share of the town in each.
| ZIP | Post office name | Share of Mount Airy | ZIP’s residents in Mount Airy |
|---|---|---|---|
| 21771 | Mount Airy, MD | 100% | 31% |
Census 2020 ZIP Code Tabulation Areas, by census block; post office names: GeoNames (CC BY 4.0). ZIPs created since 2020 are missing.
Getting around, the ER and the library
One line each; the subject pages have the rest.
ER: CMS hospital data. Library: IMLS Public Libraries Survey, FY2024.
Questions about living in Mount Airy
Who supplies Mount Airy’s drinking water, and has it had violations?
The Town of Mount Airy water system (EPA ID MD0060007). It reported no health-based violations to EPA in the five years to October 2026; 80% of systems its size had none. Its latest lead 90th percentile was 1.4 ppb (Jan 2022–Dec 2024), against a 15 ppb action level.
Who provides electricity in Mount Airy?
Potomac Edison (The Potomac Edison Co.), an investor-owned utility. Its homes paid about 15.4¢ per kWh in 2025 (EIA).
What internet providers serve Mount Airy?
Xfinity, Verizon, AT&T, T-Mobile (FCC, as of December 2025).
What ZIP codes are in Mount Airy?
21771. Census 2020 ZIP Code Tabulation Areas.
What school district is Mount Airy in?
Carroll County Public Schools. Parts of the city are in Frederick County Public Schools.
How do I register to vote in Mount Airy?
In Maryland you can register online until 21 days before Election Day, in person up to and including Election Day, or by mail (postmarked 21 days before). Elections here are run by the Carroll County Board of Elections. Check your registration at voterservices.elections.maryland.gov.
Sources & dates
Every answer above names its source. Here they are with their dates.
- Water: EPA SDWIS (Envirofacts, pulled Oct 9, 2026), ECHO SDWA 2026Q3, EPA CWS Service Area Boundaries v3.0.
- Power: HIFLD Electric Retail Service Territories (map Aug 2023); EIA-861 final 2025.
- Trash: OpenStreetMap, Geofabrik extract of Oct 9, 2026. © OpenStreetMap contributors (ODbL).
- ZIP codes: Census 2020 ZCTA relationship files; GeoNames postal codes (CC BY 4.0).
- Schools: NCES Common Core of Data, 2024–25.
- Registration: vote.gov, updated Mar 11, 2026 (read Oct 10, 2026). Official sites and area codes: Wikidata.
- Election office: FVAP local election office directory (fetched Oct 10, 2026; each record dated), EAC EAVS 2024 jurisdictions; registration and lookup links from vote.gov’s state data, checked Oct 10, 2026.
- Internet: FCC National Broadband Map, as of December 2025.