ZIP code 21043: Ellicott City, MD
ZIP code 21043 is in Ellicott City (71% of residents), Ilchester (27%) and Catonsville (2.1%), in Howard County (98%) and Baltimore County (2.1%), Maryland. It is in Maryland's 3rd congressional district (98%) and Maryland's 2nd congressional district (2.1%). Its state senate districts are State Senate District 9 (67%), State Senate District 12 (28%), State Senate District 13 (2.3%) and State Senate District 10 (2.1%); its state house districts are State Legislative Subdistrict 9B (59%), State Legislative Subdistrict 12A (28%), State Legislative Subdistrict 9A (8.6%), State Legislative District 13 (2.3%) and State Legislative District 10 (2.1%).
See it on the mapAll of Maryland
City and county
| City or town | Share of ZIP residents |
|---|---|
| Ellicott City | 71% |
| Ilchester | 27% |
| Catonsville | 2.1% |
| Columbia | 0.4% |
| County | Share of ZIP residents |
|---|---|
| Howard County | 98% |
| Baltimore County | 2.1% |
| Town or county subdivision | Share of ZIP residents |
|---|---|
| District 2, Ellicott City | 71% |
| District 1, Elkridge | 27% |
| District 1 | 2.1% |
Congressional districts
| Congressional district | Share of ZIP residents |
|---|---|
| Maryland's 3rd congressional district (MD-03) | 98% |
| Maryland's 2nd congressional district (MD-02) | 2.1% |
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-03) | Sarah Elfreth (D) | 202-225-4016 | 98% |
| U.S. Representative (MD-02) | Johnny Olszewski, Jr. (D) | 202-225-3061 | 2.1% |
| 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 |
Plus 15 state legislators across 9 districts. Look up an address for the exact ones.
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
- Ellicott City laws: search for the Ellicott City, Maryland code of ordinances
- Ilchester laws: search for the Ilchester, Maryland code of ordinances
- Catonsville laws: search for the Catonsville, Maryland code of ordinances
- Howard County website: https://www.howardcountymd.gov/
- Howard County laws: search for the Howard County, Maryland code of ordinances
- 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 9 | 67% |
| State Senate District 12 | 28% |
| State Senate District 13 | 2.3% |
| State Senate District 10 | 2.1% |
| State house district | Share of ZIP residents |
|---|---|
| State Legislative Subdistrict 9B | 59% |
| State Legislative Subdistrict 12A | 28% |
| State Legislative Subdistrict 9A | 8.6% |
| State Legislative District 13 | 2.3% |
| State Legislative District 10 | 2.1% |
Voting precincts
13 voting precincts overlap ZIP 21043. 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:21043")
ZIP 21043 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.