County ZIP codes · Indiana · FIPS 18089
Lake County, IN ZIP Codes
Lake County, Indiana has 33 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026): 28 residential and 5 for PO boxes or a single organization. 27 of the residential ones lie mainly in Lake County and 1 mainly in a neighboring county; 4 cross the county line. Median household income ranges from $28,526 in 46407 (Gary) to $127,146 in 46373 (Saint John) (Census Bureau, ACS 2020-2024).
- ACS2020-24
- Census2020
Where are the ZIP codes of Lake County?
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 $44,667 and $84,211.
They carry 19 postal town names.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013).
All 28 residential ZIP codes in Lake County
27 ZIP codes lie mainly in Lake County; 1 more reaches into it from a neighboring county and follows the first table.
| In this county | ||||||
|---|---|---|---|---|---|---|
| 46307 | Crown Point | 71,673 | 822 | $108k | $324k | 97% |
| 46410 | Merrillville | 39,243 | 1,306 | $64k | $208k | 100% |
| 46342 | Hobart | 32,224 | 920 | $76k | $213k | 72% |
| 46312 | East Chicago | 26,022 | 1,844 | $42k | $105k | 100% |
| 46375 | Schererville | 24,188 | 1,896 | $93k | $315k | 100% |
| 46321 | Munster | 23,733 | 3,125 | $110k | $334k | 100% |
| 46322 | Highland | 23,680 | 3,434 | $78k | $233k | 100% |
| 46311 | Dyer | 23,321 | 1,851 | $117k | $332k | 100% |
| 46323 | Hammond | 23,047 | 3,717 | $60k | $166k | 100% |
| 46324 | Hammond | 21,409 | 4,910 | $63k | $159k | 100% |
| 46356 | Lowell | 19,721 | 175 | $89k | $282k | 100% |
| 46373 | Saint John | 18,843 | 1,732 | $127k | $409k | 100% |
| 46319 | Griffith | 17,847 | 1,863 | $75k | $203k | 100% |
| 46303 | Cedar Lake | 17,680 | 616 | $84k | $294k | 100% |
| 46408 | Gary | 15,747 | 1,617 | $48k | $103k | 100% |
| 46404 | Gary | 15,428 | 2,568 | $42k | $95k | 100% |
| 46320 | Hammond | 14,353 | 3,082 | $37k | $135k | 100% |
| 46405 | Lake Station | 12,184 | 1,350 | $61k | $139k | 100% |
| 46394 | Whiting | 11,894 | 2,502 | $66k | $173k | 100% |
| 46403 | Gary | 10,929 | 1,183 | $46k | $178k | 90% |
| 46327 | Hammond | 10,597 | 2,303 | $47k | $142k | 100% |
| 46406 | Gary | 9,001 | 668 | $36k | $92k | 100% |
| 46407 | Gary | 8,577 | 2,054 | $29k | $60k | 100% |
| 46409 | Gary | 7,184 | 2,007 | $45k | $79k | 100% |
| 46402 | Gary | 5,836 | 692 | $34k | $85k | 100% |
| 46376 | Schneider | 319 | 36 | $64k | $188k | 100% |
| 46377 | Shelby | 45 | 217 | $39k | – | 100% |
Partly in Lake County
| In this county | ||||||
|---|---|---|---|---|---|---|
| 46341 | Hebron | 10,048 | 105 | $90k | $269k | 49% |
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?
4 ZIP codes of Lake County extend into another county. A ZIP code follows mail routes, not county borders.
| ZIP | In Lake | Elsewhere |
|---|---|---|
| 46307 | 97% | Porter County 3% |
| 46342 | 72% | Porter County 28% |
| 46403 | 90% | Porter County 10% |
| 46341 | 49% | Porter County 50%; Jasper County 1% |
Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).
PO Box and single-organization ZIP codes
Source: GeoNames postal codes (CC BY 4.0).
Which first three digits do Lake County's ZIP codes use?
The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Lake County's ZIP codes use 2 prefixes: 463 and 464.
Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.