ZIP Codes of Piatt County, IL

Population & People
Population & People
Total Population
16,035
Household Income
Household Income
Median Income
$83,468
Housing
Housing
Total Housing Units
7,082
Business & Economy
Business & Economy
Total Businesses
326
Employment
Employment
Employment Rate
63.70%
Education
Education
Bachelor's Degree+
33.64%
Source: U.S. Census ACS 2024 5-Year Estimates · rolled up across the 10 ZIPs in this county.
Data Last Updated: July 1, 2026
ZIP Codes:10 ZIP Codes (9 Standard, 1 PO Box, 0 Unique) [See All]
Area Codes:217 / 447
Timezone:Central (GMT -06:00)
Local Time:11:53:20 PM
Population:16,035 [See All]
FIPS:17147
CBSA:Champaign-Urbana, IL
Land Area:416 sq mi
Water Area:0 sq mi
Coordinates:39.9807, -88.6224
Quick Link:
https://www.zip-codes.com/county/il-piatt.asp
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Striking education divide
Bachelor's share spans 9.9% to 46.7% — a 37-point gap.

Standout ZIPs in this County


Most Populous
Monticello · 8,226 people
51.3% of county total
Highest Income
White Heath · $106,250 median
1.3× county average
Largest Land Area
Monticello · 100.5 sq mi
Spans the most ground
Fastest Growth
Monticello · 12.0% (10-yr)
7,344 → 8,226 residents
Most Educated
Monticello · 42.6% bachelor's+
2,601 of 6,100 adults 25+

Things worth knowing about Piatt County


16,035 residents live across 10 ZIPs covering 416 sq mi, served by 10 distinct USPS-recognized cities.

Population moved from 15,827 to 16,035 from 2014 to 2024 — a +1.3% change. 4 ZIPs gained residents, 6 lost.

The county's wealthiest ZIP 61884 (White Heath, $106,250 median) and poorest ZIP 61839 (De Land, $56,389) are 8.2 miles apart — a 1.9× income gap across local geography.

Median home values vary 3.0× across this county — from $86,800 in 61936 (La Place) to $258,300 in 61884 (White Heath).

Density varies 14× across the county — from 15 people/sq mi in 61839 (De Land) to 212 in 61936 (La Place).

Educational attainment ranges from 9.9% bachelor's+ in 61839 (De Land) to 46.7% in 61884 (White Heath) — the breadth of educational profiles across the area.

Within Illinois, this is the #65 most populous of 102 counties and ranks #18 for median household income .

Weighted by population, the typical household earns about $94,073 across the county — reflecting what a typical resident sees, not a simple ZIP average.

33.6% of adults age 25+ hold a bachelor's degree or higher (3,891 of 11,568 reporting).

9 Standard delivery, 1 PO Box only, 0 single-entity Unique ZIPs serve this county.

All ZIP Codes in Piatt County


ZIPCityTypePopulationMedian IncomeArea (sq mi)10-yr Growth
61856MonticelloStandard8,226$103,559100.512.0%
61813BementStandard2,043$84,06368.14.7%
61818Cerro GordoStandard1,560$84,37545.30.2%
61854MansfieldStandard1,299$86,70556.0-16.0%
61884White HeathStandard973$106,25025.9-16.7%
61929HammondStandard672$79,16737.2-2.6%
61839De LandStandard558$56,38937.1-18.2%
61830CiscoStandard510$67,23233.5-3.4%
61936La PlacePO Box1700.827.8%
61855MilmineStandard2411.2-89.4%

Adjacent & Nearby Counties