ZIP Codes of Washtenaw County, MI

Population & People
Population & People
Total Population
355,280
Household Income
Household Income
Median Income
$86,363
Housing
Housing
Total Housing Units
154,312
Business & Economy
Business & Economy
Total Businesses
8,107
Employment
Employment
Employment Rate
60.31%
Education
Education
Bachelor's Degree+
59.92%
Source: U.S. Census ACS 2024 5-Year Estimates · rolled up across the 19 ZIPs in this county.
Data Last Updated: July 1, 2026
ZIP Codes:19 ZIP Codes (13 Standard, 6 PO Box, 0 Unique) [See All]
Area Code:734
Timezone:Eastern (GMT -05:00)
Local Time:11:53:53 PM
Population:355,280 [See All]
FIPS:26161
CBSA:Ann Arbor, MI
Land Area:601 sq mi
Water Area:13 sq mi
Coordinates:42.2567, -83.7577
Quick Link:
https://www.zip-codes.com/county/mi-washtenaw.asp
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Michigan's most-educated county
59.9% of adults 25+ have a bachelor's degree+.
Sharp income gradient
Wealthiest ZIP earns 9.2× the poorest — $129,254 vs $14,093.
Michigan's most foreign-born county
13.3% of residents are foreign-born.
Extreme geographic sprawl
The largest ZIP spans 385× the smallest by area — 95.2 sq mi down to 0.25.
Extreme education divide
Bachelor's share ranges 24.4% to 82.7% across ZIPs — a 58-point gap.
Among Michigan's 5 densest counties
591 people per square mile (#5 statewide).

Standout ZIPs in this County


Most Populous
Ypsilanti · 66,525 people
18.7% of county total
Highest Income
Dexter · $129,254 median
1.5× county average
Largest Land Area
Manchester · 95.2 sq mi
Spans the most ground
Fastest Growth
Dexter · 11.7% (10-yr)
15,209 → 16,986 residents
Most Educated
Ann Arbor · 82.7% bachelor's+
19,447 of 23,502 adults 25+

Things worth knowing about Washtenaw County


355,280 residents live across 19 ZIPs covering 601 sq mi, served by 11 distinct USPS-recognized cities.

Population moved from 337,855 to 355,280 from 2014 to 2024 — a +5.2% change. 11 ZIPs gained residents, 3 lost.

The county's wealthiest ZIP 48130 (Dexter, $129,254 median) and poorest ZIP 48109 (Ann Arbor, $14,093) are 9.9 miles apart — a 9.2× income gap across local geography.

Median home values vary 2.7× across this county — from $189,100 in 48198 (Ypsilanti) to $503,100 in 48105 (Ann Arbor).

Density varies 294× across the county — from 82 people/sq mi in 48158 (Manchester) to 24,006 in 48109 (Ann Arbor).

Educational attainment ranges from 24.4% bachelor's+ in 48191 (Willis) to 82.7% in 48105 (Ann Arbor) — the breadth of educational profiles across the area.

Within Michigan, this is the #6 most populous of 83 counties and ranks #6 for median household income with the #13 fastest decade growth .

Weighted by population, the typical household earns about $87,616 across the county — reflecting what a typical resident sees, not a simple ZIP average.

59.9% of adults age 25+ hold a bachelor's degree or higher (135,904 of 226,812 reporting). The most-educated ZIPs cluster around Ann Arbor.

13 Standard delivery, 6 PO Box only, 0 single-entity Unique ZIPs serve this county.

Stories about Washtenaw County


Higher-education hub

7 ZIPs in this county where more than 60% of adults 25+ hold a bachelor's degree — typically college campuses, research enclaves, or tech corridors.

Ann Arbor
82.7%
37,048 residents
Ann Arbor
80.9%
43,979 residents
Ann Arbor
77.8%
5,939 residents
Ann Arbor
75.3%
55,054 residents
Dexter
66.6%
16,986 residents
Ann Arbor
65.9%
27,666 residents
Saline
60.2%
23,451 residents

Two counties in one

Median household income spans 9.2× between the wealthiest and poorest ZIPs — a sign of significant intra-county inequality.

Wealthiest ZIP
Dexter
Median income: $129,254
Population: 16,986
Bachelor's+: 66.6%
vs
Poorest ZIP (pop >= 500)
Ann Arbor
Median income: $14,093
Population: 5,939
Bachelor's+: 77.8%
For every $1 of household income in 48109, the typical household in 48130 earns $9.17.

All ZIP Codes in Washtenaw County


ZIPCityTypePopulationMedian IncomeArea (sq mi)10-yr Growth
48197YpsilantiStandard66,525$73,73742.35.0%
48103Ann ArborStandard55,054$116,19466.90.5%
48104Ann ArborStandard43,979$64,2318.511.7%
48198YpsilantiStandard39,244$63,32634.13.6%
48105Ann ArborStandard37,048$94,77452.38.4%
48108Ann ArborStandard27,666$89,35516.74.8%
48176SalineStandard23,451$114,20677.39.4%
48130DexterStandard16,986$129,25465.411.7%
48189Whitmore LakeStandard13,893$87,14535.5-0.6%
48118ChelseaStandard13,246$88,27889.93.8%
48158ManchesterStandard7,770$94,78495.2-0.3%
48109Ann ArborStandard5,939$14,0930.2-10.3%
48191WillisStandard4,403$102,83315.49.7%
48190WhittakerPO Box76$76,8751.122.6%
48115BridgewaterPO Box0.0
48106Ann ArborPO Box0.0
48113Ann ArborPO Box0.0
48107Ann ArborPO Box0.0
48175SalemPO Box0.0

Adjacent & Nearby Counties