First three digits · Iowa
ZIP Codes Starting with
55 ZIP codes start with 503, sorted at the Des Moines, IA (SCF 500) sectional center (USPS labeling list L005, effective October 1, 2026) in Iowa: 17 residential ZIP codes across 2 counties and 38 PO Box or single-organization codes (Census 2020 ZCTAs and GeoNames postal codes, October 2026).
What do the digits 503 mean?
The first digit, 5, is one of ten national areas (Iowa, Minnesota, Montana, North Dakota, South Dakota and Wisconsin). The first three, 503, route mail to a sectional center: USPS labeling list L005 (effective October 1, 2026) sends letters for 503 to the Des Moines, IA (SCF 500) facility. The last two digits pick the delivery area. By residents, the largest town names among the 503 ZIP codes are Des Moines, Urbandale, Clive, Pleasant Hill and Windsor Heights.
The same facility sorts 9 prefixes, 450 ZIP codes in all: 500, 501, 502, 503, 505, 508, 509, 514, 525.
Where are the 503 ZIP codes?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
All ZIP codes starting with 503
| County | ||||||
|---|---|---|---|---|---|---|
| 50301 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50302 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50303 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50304 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50305 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50306 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50307 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50308 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50309 | Des Moines | Polk County | 10,110 | 3,725 | $57k | $293k |
| 50310 | Des Moines | Polk County | 31,177 | 3,880 | $76k | $223k |
| 50311 | Des Moines | Polk County | 14,574 | 5,711 | $62k | $227k |
| 50312 | Des Moines | Polk County | 15,802 | 2,807 | $92k | $292k |
| 50313 | Des Moines | Polk County | 17,440 | 966 | $68k | $175k |
| 50314 | Des Moines | Polk County | 10,438 | 4,228 | $40k | $148k |
| 50315 | Des Moines | Polk County | 34,816 | 3,381 | $61k | $173k |
| 50316 | Des Moines | Polk County | 16,710 | 4,685 | $56k | $154k |
| 50317 | Des Moines | Polk County | 36,548 | 1,652 | $66k | $178k |
| 50318 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50319 | Des Moines | Polk County | no residents | 0 | – | – |
| 50320 | Des Moines | Polk County | 24,807 | 1,477 | $85k | $217k |
| 50321 | Des Moines | Polk County | 7,900 | 697 | $80k | $321k |
| 50322 | Urbandale | Polk County | 31,931 | 2,950 | $92k | $276k |
| 50323 | Urbandale | Dallas County | 17,265 | 1,706 | $176k | $487k |
| 50324 | Windsor Heights | Polk County | 5,143 | 3,663 | $92k | $268k |
| 50325 | Clive | Polk County | 19,012 | 2,462 | $132k | $401k |
| 50327 | Pleasant Hill | Polk County | 13,177 | 835 | $98k | $314k |
| 50328 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50329 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50330 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50331 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50332 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50333 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50334 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50335 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50336 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50339 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50340 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50359 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50360 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50361 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50362 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50363 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50364 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50367 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50368 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50369 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50380 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50381 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50391 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50392 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50393 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50394 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50395 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50396 | Des Moines | Polk County | PO Box or unique | – | – | – |
| 50398 | Urbandale | Polk County | PO Box or unique | – | – | – |
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; GeoNames postal codes (CC BY 4.0) for codes without a residential area.