Boundary Atlas

ZIP code 20171: McNair, VA

ZIP code 20171 is in McNair (42% of residents), Franklin Farm (32%), Floris (16%), Difficult Run (5.3%) and Sully Square (4.4%), in Fairfax County, Virginia. It is in Virginia's 11th congressional district. Its state senate districts are State Senate District 36 (48%), State Senate District 38 (47%) and State Senate District 37 (5.3%); its state house districts are House of Delegates District 8 (90%), House of Delegates District 7 (5.3%) and House of Delegates District 9 (4.4%).

51,759residents (2020 Census)
11.6 sq miland area
6cities and towns
1congressional district
15voting precincts

See it on the mapAll of Virginia

City and county

City or townShare of ZIP residents
McNair42%
Franklin Farm32%
Floris16%
Difficult Run5.3%
Sully Square4.4%
Navy0.6%

CountyShare of ZIP residents
Fairfax County100%

Town or county subdivisionShare of ZIP residents
Hunter Mill district49%
Sully district32%
Dranesville district19%

Congressional district

Congressional districtShare of ZIP residents
Virginia's 11th congressional district (VA-11)100%

State legislative districts

State senate districtShare of ZIP residents
State Senate District 3648%
State Senate District 3847%
State Senate District 375.3%

State house districtShare of ZIP residents
House of Delegates District 890%
House of Delegates District 75.3%
House of Delegates District 94.4%

Voting precincts

15 voting precincts overlap ZIP 20171. 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:20171")

ZIP 20171 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.