How pages are produced
PlainZIP's ZIP-code, city, county, and state pages are generated from documented public datasets — primarily the U.S. Census Bureau's American Community Survey (ACS) 5-Year Estimates. We pull each release's tables directly from the Census Bureau Developer API for every ZIP Code Tabulation Area (ZCTA), load them into a structured database, and render each geographic page from that database. The figures you see — population, median household income, education, housing tenure, and commute patterns — are computed from the Census Bureau's numbers, not hand-typed and not estimated by us.
This is a data-publishing model: the same template renders tens of thousands of pages so that every ZIP code is covered consistently. We are transparent that these data pages are produced programmatically from the source datasets rather than written individually. The editorial work goes into the pipeline (how data is sourced, normalized, and computed), the methodology, and the written guides — not into hand-authoring 33,000 near-identical ZIP pages, which would add no accuracy and invite inconsistency.
Sourcing standards
- Primary sources only. Demographic, income, education, and housing figures come from the Census Bureau's published ACS 5-Year Estimates. ZIP-to-county and city mapping uses the HUD USPS Crosswalk; county employment context comes from the BLS Quarterly Census of Employment and Wages, as documented in our methodology.
- Attribution in context. Each data page names its dataset and survey vintage near the figures, and links to the methodology that explains how the ACS is collected and what a ZCTA is.
- Derived values are labeled. Numbers we compute ourselves — national percentile rankings, distribution placements, peer comparisons — are presented as our analysis of Census data, distinct from the Census Bureau's published estimates.
- No invented data. Where a value is unavailable for an area — a ZIP code with no corresponding ZCTA, or a small-population area the ACS does not publish — the page says so rather than filling the gap with an estimate.
Update cadence
The Census Bureau publishes new ACS 5-Year Estimates once a year, typically in December, each reflecting the most recent five-year survey period. We refresh our database within about 30 days of each new release and recompute the national distributions and rankings that pages reference. Between releases the figures are stable because the source itself does not change; because the 5-Year Estimates pool five years of responses, rapidly changing neighborhoods can lag, which is why our pages frame ACS data as a smoothed multi-year estimate rather than a point-in-time snapshot. The survey vintage is shown on every data page.
Corrections process
If a figure on PlainZIP looks wrong, please tell us. Because our pages are generated from the Census dataset, a genuine error almost always traces back to either the source data or our processing of it — so this is how we handle a report:
- Report. Email us through the contact page with the page URL and the number that looks off.
- Verify. We compare the figure against the Census Bureau's published ACS table for that ZCTA and survey year.
- Fix at the source. If the value is wrong on our side, we correct it in the database and pipeline that generate the page — not just on the single page — so every affected page is fixed at once. If the figure faithfully reflects the Census Bureau's published estimate, we explain that and, where useful, add context about margins of error.
- Note it. Material corrections that change a published figure are reflected the next time the page rebuilds, with the survey vintage shown so you can see which release a page is based on.
We aim to acknowledge data-error reports within a few business days.
Editorial independence
PlainZIP is an independent publisher and is not affiliated with the U.S. Census Bureau, HUD, or any government agency. Our guides and analysis are not influenced by advertisers; advertising, where present, is clearly distinguishable from editorial content and never determines which ZIP codes, rankings, or figures we show. Our rankings are computed mechanically from Census figures, so no area can pay to move up a list.
Appropriate use
PlainZIP is for informational and research purposes only and does not constitute financial, real-estate, or relocation advice. ACS figures are statistical estimates with published margins of error — larger, more populous ZCTAs produce more precise estimates than small ones. For a decision that depends on a specific number — a mortgage, a move, a school choice — confirm the current figure against the underlying Census data and consult a qualified professional.