ZIP code 20878: Gaithersburg, MD
ZIP code 20878 is in Gaithersburg (58% of residents), North Potomac (27%), Darnestown (6.2%) and Travilah (1.4%), in Montgomery County, Maryland. 7.2% of its residents live outside city limits. It is in Maryland's 6th congressional district (68%) and Maryland's 8th congressional district (32%). Its state senate districts are State Senate District 17 (56%), State Senate District 15 (32%) and State Senate District 39 (11%); its state house districts are State Legislative District 17 (56%), State Legislative District 15 (32%) and State Legislative District 39 (11%).
See it on the mapAll of Maryland
City and county
| City or town | Share of ZIP residents |
|---|---|
| Gaithersburg | 58% |
| North Potomac | 27% |
| Darnestown | 6.2% |
| Travilah | 1.4% |
| County | Share of ZIP residents |
|---|---|
| Montgomery County | 100% |
| Town or county subdivision | Share of ZIP residents |
|---|---|
| District 9 | 63% |
| District 6 | 37% |
Congressional districts
| Congressional district | Share of ZIP residents |
|---|---|
| Maryland's 6th congressional district (MD-06) | 68% |
| Maryland's 8th congressional district (MD-08) | 32% |
This ZIP is split between districts. A mailing address in it could be in either; the map or locate_point gives the district for an exact address.
Elected officials
| Office | Member | Contact | Share of residents |
|---|---|---|---|
| U.S. Representative (MD-06) | April McClain Delaney (D) | 202-225-2721 | 68% |
| U.S. Representative (MD-08) | Jamie Raskin (D) | 202-225-5341 | 32% |
| U.S. Senator | Angela D. Alsobrooks (D) | 202-224-4524 · contact form | statewide |
| U.S. Senator | Chris Van Hollen (D) | 202-224-4654 · contact form | statewide |
| State Senator (State Senate District 17) | Cheryl Kagan (Democratic) | 56% | |
| State Senator (State Senate District 15) | Brian Feldman (Democratic) | 32% | |
| State Senator (State Senate District 39) | Nancy King (Democratic) | 11% | |
| Delegate (State Legislative District 17) | Joe Vogel (Democratic) | 56% | |
| Delegate (State Legislative District 17) | Julie Palakovich Carr (Democratic) | 56% | |
| Delegate (State Legislative District 17) | Ryan Spiegel (Democratic) | 56% | |
| Delegate (State Legislative District 15) | David Fraser-Hidalgo (Democratic) | 32% | |
| Delegate (State Legislative District 15) | Lily Qi (Democratic) | 32% | |
| Delegate (State Legislative District 15) | Linda Foley (Democratic) | 32% | |
| Delegate (State Legislative District 39) | Gabriel Acevero (Democratic) | 11% | |
| Delegate (State Legislative District 39) | Greg Wims (Democratic) | 11% | |
| Delegate (State Legislative District 39) | Lesley Lopez (Democratic) | 11% |
Officials serving now (members of Congress until January 3, 2027). Sources: State legislators: Open States (public domain); Members of Congress: the @unitedstates project, congress-legislators (CC0).
Local government
- Gaithersburg website: https://www.gaithersburgmd.gov/
- Gaithersburg laws: search for the Gaithersburg, Maryland code of ordinances
- North Potomac laws: search for the North Potomac, Maryland code of ordinances
- Darnestown laws: search for the Darnestown, Maryland code of ordinances
- Montgomery County website: https://www.montgomerycountymd.gov/
- Montgomery County laws: search for the Montgomery County, Maryland code of ordinances
State legislative districts
| State senate district | Share of ZIP residents |
|---|---|
| State Senate District 17 | 56% |
| State Senate District 15 | 32% |
| State Senate District 39 | 11% |
| State house district | Share of ZIP residents |
|---|---|
| State Legislative District 17 | 56% |
| State Legislative District 15 | 32% |
| State Legislative District 39 | 11% |
Voting precincts
18 voting precincts overlap ZIP 20878. Map them, with each precinct's share of the ZIP's residents.
Get this in your AI agent
Your agent can get these cities, counties, districts and precincts with their shares, and their GeoJSON boundaries, from Boundary Atlas. Add https://atlas-production-d344.up.railway.app/mcp to Claude, ChatGPT, Cursor or Codex (free, no key; how), then:
related_geographies(id="us:zcta:20878")
ZIP 20878 here is the Census Bureau's ZIP Code Tabulation Area, which approximates the USPS ZIP Code; PO-box-only ZIPs have none. Districts are the maps in force for the November 3, 2026 election.