ZIP code 77521: Baytown, TX
ZIP code 77521 is in Baytown (70% of residents), in Harris County (95%) and Chambers County (5.4%), Texas. 30% of its residents live outside city limits. It is in Texas's 9th congressional district (85%) and Texas's 36th congressional district (15%). Its state senate districts are State Senate District 11 (46%), State Senate District 4 (30%) and State Senate District 6 (24%); its state house districts are State House District 128 (91%), State House District 23 (5.4%) and State House District 143 (3.8%).
City and county
| City or town | Share of ZIP residents |
|---|---|
| Baytown | 70% |
| County | Share of ZIP residents |
|---|---|
| Harris County | 95% |
| Chambers County | 5.4% |
| Town or county subdivision | Share of ZIP residents |
|---|---|
| Baytown CCD | 68% |
| Northeast Harris CCD | 27% |
| Mont Belvieu CCD | 5.4% |
Congressional districts
| Congressional district | Share of ZIP residents |
|---|---|
| Texas's 9th congressional district (TX-09) | 85% |
| Texas's 36th congressional district (TX-36) | 15% |
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 (TX-09) | Al Green (D) | 202-225-7508 | 85% |
| U.S. Representative (TX-36) | Brian Babin (R) | 202-225-1555 | 15% |
| U.S. Senator | John Cornyn (R) | 202-224-2934 · contact form | statewide |
| U.S. Senator | Ted Cruz (R) | 202-224-5922 · contact form | statewide |
| State Senator (State Senate District 11) | Mayes Middleton (R) | 46% | |
| State Senator (State Senate District 4) | Brett Ligon (R) | 30% | |
| State Senator (State Senate District 6) | Carol Alvarado (Democratic) | 713-926-6257 | 24% |
| State Representative (State House District 128) | Briscoe Cain (R) | 346-499-7036 | 91% |
| State Representative (State House District 23) | Terri Leo-Wilson (R) | 409-762-0202 | 5.4% |
| State Representative (State House District 143) | Ana Hernandez (Democratic) | 713-675-8596 | 3.8% |
Elected in 2024 under TX's previous congressional map; this district's lines changed for the 120th Congress (seated January 3, 2027).
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
- Baytown website: http://www.baytown.org
- Baytown laws: search for the Baytown, Texas code of ordinances
- Harris County website: https://harriscountytx.gov
- Harris County laws: search for the Harris County, Texas code of ordinances
- Chambers County website: https://www.chamberscountytx.gov/
- Chambers County laws: search for the Chambers County, Texas code of ordinances
State legislative districts
| State senate district | Share of ZIP residents |
|---|---|
| State Senate District 11 | 46% |
| State Senate District 4 | 30% |
| State Senate District 6 | 24% |
| State house district | Share of ZIP residents |
|---|---|
| State House District 128 | 91% |
| State House District 23 | 5.4% |
| State House District 143 | 3.8% |
Voting precincts
19 voting precincts overlap ZIP 77521. 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:77521")
ZIP 77521 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.