ZIP code 21131: District 10, MD
ZIP code 21131 is in Baltimore County, Maryland, outside any city or Census-designated place. It is in Maryland's 1st congressional district (67%) and Maryland's 2nd congressional district (33%). Its state senate district is State Senate District 42; its state house districts are State Legislative Subdistrict 42A (97%) and State Legislative Subdistrict 42B (2.6%).
See it on the mapAll of Maryland
City and county
| City or town | Share of ZIP residents |
|---|---|
| Cockeysville | 0.7% |
| County | Share of ZIP residents |
|---|---|
| Baltimore County | 100% |
| Town or county subdivision | Share of ZIP residents |
|---|---|
| District 10 | 93% |
| District 11 | 4.9% |
| District 8 | 2.6% |
Congressional districts
| Congressional district | Share of ZIP residents |
|---|---|
| Maryland's 1st congressional district (MD-01) | 67% |
| Maryland's 2nd congressional district (MD-02) | 33% |
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-01) | Andy Harris (R) | 202-225-5311 | 67% |
| U.S. Representative (MD-02) | Johnny Olszewski, Jr. (D) | 202-225-3061 | 33% |
| 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 42) | Chris West (R) | 100% | |
| Delegate (State Legislative Subdistrict 42A) | Alex Harlan (R) | 97% | |
| Delegate (State Legislative Subdistrict 42B) | Michele Guyton (Democratic) | 2.6% |
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
- Baltimore County website: https://www.baltimorecountymd.gov/
- Baltimore County laws: search for the Baltimore County, Maryland code of ordinances
State legislative districts
| State senate district | Share of ZIP residents |
|---|---|
| State Senate District 42 | 100% |
| State house district | Share of ZIP residents |
|---|---|
| State Legislative Subdistrict 42A | 97% |
| State Legislative Subdistrict 42B | 2.6% |
Voting precincts
7 voting precincts overlap ZIP 21131. 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:21131")
ZIP 21131 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.