Research & Coverage
PlainZIP indexes 33,099 U.S. ZIP codes covering a combined population of 312,447,629 across 52 states and 34 timezones. Every number on this page is computed from our own database at request time — see methodology for source detail.
Coverage by state (top 10 by ZIP count)
Counts come from SELECT state_fips, COUNT(*), SUM(population) FROM zips GROUP BY state_fips ORDER BY COUNT(*) DESC LIMIT 10
— Census ACS 2023 5-Year Estimates joined to the HUD-USPS ZIP crosswalk.
| State FIPS | ZIP count | Population |
|---|---|---|
| 48 | 1,935 | 25,144,800 |
| 42 | 1,795 | 12,702,102 |
| 36 | 1,794 | 19,378,077 |
| 06 | 1,761 | 37,249,464 |
| 17 | 1,383 | 12,830,581 |
| 39 | 1,195 | 11,535,123 |
| 29 | 1,022 | 5,989,092 |
| 26 | 986 | 9,883,612 |
| 12 | 983 | 18,801,226 |
| 19 | 934 | 3,046,945 |
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We are intentionally publishing only data we can derive directly from primary federal sources. Previously published analyst-style pages were withdrawn during a 2026-05 data-integrity audit and will be reissued only when each statistic is queryable from this database. Until then, use the entity-level pages below.
Source: U.S. Census Bureau ACS 5-Year Estimates (2023) and HUD-USPS ZIP crosswalk. Verify with HUD →