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County ZIP codes · Missouri · FIPS 29211

Sullivan County, MO ZIP Codes

Sullivan County, Missouri has 13 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026), all residential. 7 of the residential ones lie mainly in Sullivan County and 6 mainly in a neighboring county; 11 cross the county line. Median household income ranges from $44,167 in 63544 (Green Castle) to $69,643 in 63565 (Unionville) (Census Bureau, ACS 2020-2024).

  • ACS2020-24
  • Census2020

Where are the ZIP codes of Sullivan County?

63544 · Green Castle: $44k63545 · Green City: $40k63556 · Milan: $59k63557 · New Boston: $61k63560 · Pollock: $57k63565 · Unionville: $70k63566 · Winigan: $97k64630 · Browning: $58k64641 · Galt: $50k64645 · Harris: $53k64646 · Humphreys: $68k64652 · Laredo: $59k64667 · Newtown: $48k6355663565635446463063545635576464164667646456464664652635606356663544 · Green Castle: $44k63545 · Green City: $40k63556 · Milan: $59k63557 · New Boston: $61k63560 · Pollock: $57k63565 · Unionville: $70k63566 · Winigan: $97k64630 · Browning: $58k64641 · Galt: $50k64645 · Harris: $53k64646 · Humphreys: $68k64652 · Laredo: $59k64667 · Newtown: $48k6355663565635446463063545635576464164667646456464664652635606356663544 · Green Castle: $44k63545 · Green City: $40k63556 · Milan: $59k63557 · New Boston: $61k63560 · Pollock: $57k63565 · Unionville: $70k63566 · Winigan: $97k64630 · Browning: $58k64641 · Galt: $50k64645 · Harris: $53k64646 · Humphreys: $68k64652 · Laredo: $59k64667 · Newtown: $48k63556635656354464630635456355764641646676464564646646526356063566
The residential ZIP codes of Sullivan 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?

They carry 13 postal town names.

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

All 13 residential ZIP codes in Sullivan County

7 ZIP codes lie mainly in Sullivan County; 6 more reach into it from a neighboring county and follow the first table.

Residential ZIP codes mainly in Sullivan County, largest first; "In this county" is the share of the ZIP's land in the county
In this county
63556 Milan 3,196 13 $59k $124k 100%
63545 Green City 968 9 $40k $156k 100%
64630 Browning 495 5 $58k $148k 53%
64646 Humphreys 471 10 $68k – 88%
64667 Newtown 255 3 $48k $90k 38%
64645 Harris 195 3 $53k – 71%
63560 Pollock 61 2 $57k – 87%

Partly in Sullivan County

Residential ZIP codes mainly in another county that reach at least 1% into Sullivan County, by their share here
In this county
63544 Green Castle 1,159 8 $44k $109k 43%
63566 Winigan 72 4 $97k $100k 39%
64641 Galt 625 8 $50k $138k 21%
63557 New Boston 272 3 $61k $281k 3%
64652 Laredo 346 8 $59k $176k 2%
63565 Unionville 3,965 15 $70k $128k 2%

Download the 13 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?

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

Share of each ZIP code's land in Sullivan County and in the neighboring counties
ZIPIn SullivanElsewhere
635652%Putnam County98%
6354443%Adair County45%; Putnam County12%
6464121%Grundy County79%
6463053%Linn County47%
6464688%Linn County12%
646522%Grundy County97%
635573%Linn County66%; Macon County21%; Adair County9%
6466738%Mercer County35%; Putnam County27%
6464571%Mercer County29%
6356639%Linn County61%
6356087%Putnam County13%

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

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

The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Sullivan County's ZIP codes use 2 prefixes: 635 and 646.

Three-digit prefixes of Sullivan 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 Sullivan County's
PrefixSectional centerHereAll codes
635Mid-Missouri, MO (SCF 650)733
646Kansas City, MO (SCF 640)655

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