ACS PUMS RESEARCH EXPLORER · 2005–2024
U.S. Worst Case Housing Needs Explorer
Explore national and PUMA-level estimates, compare three assistance-proxy thresholds, and inspect the historical reconstruction associated with the toolkit’s approximately 10.1 million household benchmark.
2024
10.12M
Legacy ACS reconstruction · broader problem definition
20052024
Share of renter households classified under the 40% FMR assistance proxy.
Geography / data
2020 PUMA
Standard ACS 1-year PUMS
PUMA boundaries change with Census vintages. The map automatically uses the correct vintage for each year.
WCN 40 Proxy Rate by PUMA
2024 · Census 2020 PUMA geography
MAP 1
Loading map…
Source: U.S. Census Bureau ACS PUMS; HUD Income Limits and Fair Market Rents; Census PUMA geography. Quiesce.T calculations.
Worst Case Housing Needs, 2005–2024
Legacy reconstruction and WCN 30 / 40 / 50 sensitivity series
CHART 1
2024 legacy benchmark: the standardized-input reconstruction is 10,115,266 households; the historical/reference value is 10,112,494 (difference: 2,772). The legacy line uses a broader problem definition than the WCN 30 / 40 / 50 severe-cost-burden series. The 2020 experimental data point is shown separately and should not be compared directly with adjacent standard ACS years.
View the 2005–2024 values as a table
| Year | Legacy ACS reconstruction | WCN 30 | WCN 40 | WCN 50 |
|---|
Source: ACS PUMS 2005–2024, HUD income limits and Fair Market Rents; Quiesce.T reconstruction. The legacy series is an ACS-based proxy and is not HUD’s official AHS Worst Case Housing Needs series.
Methodology & Interpretation
What WCN 30 / 40 / 50 mean
Each series starts with very-low-income renter households with severe rent burden (at least 50% of income). It removes households classified as likely assisted when gross rent falls below 30%, 40%, or 50% of the applicable HUD Fair Market Rent. ACS PUMS does not identify actual subsidy receipt, so these are sensitivity estimates, not observed assistance counts.
Legacy WCN reconstruction
The legacy line uses the recovered historical problem union (severe rent burden, severe overcrowding, or a legacy inadequacy proxy), HUD very-low-income limits, and the 40% FMR assistance rule. Its 2024 value is about 10.12 million. The map’s WCN 40 series uses the severe-cost-burden parent universe and is about 9.35 million in 2024; the two definitions should not be treated as the same estimate.
Geography across time
Years 2005–2011 use Census 2000 PUMAs, 2012–2021 use Census 2010 PUMAs, and 2022–2024 use Census 2020 PUMAs. PUMAs are not directly comparable polygon-for-polygon across vintages.
2020 data note
The 2020 layer uses experimental ACS 1-year PUMS weights. The Census Bureau advises against comparing these experimental estimates with standard ACS estimates from other years. We mark the 2020 point separately in the chart and flag its map layer.
Technical notes, special geography and definitions
Louisiana 2006–2011: ACS pseudo-PUMA 77777 is displayed as the union of Census 2000 PUMAs 01801, 01802 and 01905. In 2005 the three official PUMAs are shown separately.
Rates: PUMA WCN rates use total renter households as the denominator. Count maps use year-specific quintiles; rate and rent-to-FMR maps use fixed thresholds so color meaning remains comparable across years.
Interpretation: the 30 / 40 / 50 labels denote the FMR percentage used to identify likely assistance, not an income threshold. Higher thresholds remove more households from the severe-burden parent universe. Missing values are displayed as no data.
Assistance proxy: this explorer does not observe subsidy receipt directly in ACS PUMS. Assistance status is approximated from gross rent relative to HUD FMR under the selected threshold.
Official HUD WCN: HUD’s official Worst Case Housing Needs reports are based primarily on the American Housing Survey. The legacy line shown here is an ACS reconstruction for research continuity.
Further reading: NMHC / NYU Housing Affordability Toolkit; HUD Worst Case Housing Needs reports; Census 2020 experimental ACS guidance.