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County ZIP codes · Iowa · FIPS 19019

Buchanan County, IA ZIP Codes

Buchanan County, Iowa has 15 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026), all residential. 10 of the residential ones lie mainly in Buchanan County and 5 mainly in a neighboring county; 10 cross the county line. Median household income ranges from $48,646 in 50662 (Oelwein) to $103,106 in 50629 (Fairbank) (Census Bureau, ACS 2020-2024).

  • ACS2020-24
  • Census2020

Where are the ZIP codes of Buchanan County?

50607 · Aurora: $55k50629 · Fairbank: $103k50641 · Hazleton: $67k50644 · Independence: $80k50648 · Jesup: $95k50650 · Lamont: $58k50654 · Masonville: $53k50662 · Oelwein: $49k50671 · Stanley: $57k50682 · Winthrop: $89k52210 · Brandon: $71k52218 · Coggon: $82k52326 · Quasqueton: $76k52329 · Rowley: $58k52352 · Walker: $92k506445235252218506295064850682506545060750662523295064150650522105067150607 · Aurora: $55k50629 · Fairbank: $103k50641 · Hazleton: $67k50644 · Independence: $80k50648 · Jesup: $95k50650 · Lamont: $58k50654 · Masonville: $53k50662 · Oelwein: $49k50671 · Stanley: $57k50682 · Winthrop: $89k52210 · Brandon: $71k52218 · Coggon: $82k52326 · Quasqueton: $76k52329 · Rowley: $58k52352 · Walker: $92k506445235252218506295064850682506545060750662523295064150650522105067150607 · Aurora: $55k50629 · Fairbank: $103k50641 · Hazleton: $67k50644 · Independence: $80k50648 · Jesup: $95k50650 · Lamont: $58k50654 · Masonville: $53k50662 · Oelwein: $49k50671 · Stanley: $57k50682 · Winthrop: $89k52210 · Brandon: $71k52218 · Coggon: $82k52326 · Quasqueton: $76k52329 · Rowley: $58k52352 · Walker: $92k5064452352522185062950648506825060750662523295064152210
The residential ZIP codes of Buchanan County (whole outlines, including the parts in neighboring counties), shaded by median household income in national fifths (ACS 2020-2024). <$54.1k$98.1k+no figure

Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).

How different are its ZIP codes?

The middle half of its ranked ZIP codes (1,000+ people living in households) report median household incomes between $67,115 and $92,321.

They carry 15 postal town names.

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013).

All 15 residential ZIP codes in Buchanan County

10 ZIP codes lie mainly in Buchanan County; 5 more reach into it from a neighboring county and follow the first table.

Residential ZIP codes mainly in Buchanan County, largest first; "In this county" is the share of the ZIP's land in the county
In this county
50644 Independence 8,419 58 $80k $187k 100%
50629 Fairbank 2,082 28 $103k $207k 32%
50641 Hazleton 1,950 43 $67k $156k 100%
50682 Winthrop 1,692 20 $89k $184k 100%
52210 Brandon 958 28 $71k $158k 99%
52326 Quasqueton 694 700 $76k $144k 100%
52329 Rowley 671 13 $58k $171k 100%
50650 Lamont 648 16 $58k $121k 69%
50607 Aurora 403 8 $55k $143k 70%
50654 Masonville 275 5 $53k $124k 52%

Partly in Buchanan County

Residential ZIP codes mainly in another county that reach at least 1% into Buchanan County, by their share here
In this county
50648 Jesup 4,269 51 $95k $226k 42%
50671 Stanley 182 8 $57k $108k 39%
52352 Walker 1,833 23 $92k $231k 36%
52218 Coggon 1,413 19 $82k $181k 24%
50662 Oelwein 6,576 93 $49k $108k 6%

Download the 15 ZIP codes as CSV

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; county shares by land area (Census 2020 ZCTA-county relationship file).

Which ZIP codes cross the county line?

10 ZIP codes of Buchanan County extend into another county. A ZIP code follows mail routes, not county borders.

Share of each ZIP code's land in Buchanan County and in the neighboring counties
ZIPIn BuchananElsewhere
506626%Fayette County 94%
5064842%Black Hawk County 58%
5062932%Bremer County 29%; Fayette County 22%; Black Hawk County 16%
5235236%Linn County 47%; Benton County 17%
5221824%Linn County 56%; Delaware County 20%
5221099%Benton County 1%
5065069%Fayette County 31%
5060770%Fayette County 30%
5065452%Delaware County 48%
5067139%Fayette County 61%

Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).

Which first three digits do Buchanan County's ZIP codes use?

The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Buchanan County's ZIP codes use 3 prefixes: 506, 522 and 523.

Three-digit prefixes of Buchanan County's ZIP codes, the sectional center for each (USPS labeling list L005, effective October 1, 2026) and how many of the prefix's codes are Buchanan County's
PrefixSectional centerHereAll codes
506 Waterloo, IA (SCF 506) 10 70
522 Cedar Rapids, IA (SCF 522) 2 50
523 Cedar Rapids, IA (SCF 522) 3 53

Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.