Methodology

To determine the ZIP codes with the highest poverty rates in the nation, 24/7 Wall St. reviewed five-year estimates of the percentage of people for whom poverty status had been determined as living below the poverty line from the U.S. Census Bureau’s 2019 American Community Survey.

We used ZIP Code Tabulation Areas — a census geography type which defines areal representations of United States Postal Service ZIP codes (USPS ZIP codes do not define geographic boundaries but instead are a network of mail delivery routes in a service area). We refer to Census ZCTAs as ZIP codes.

Of the 33,120 ZIP codes the Census publishes data for, 32,989 had boundaries that fell within one of the 50 states or the District of Columbia.

ZIP codes were excluded if poverty rates were not available in the 2019 ACS, if the population for which the poverty status had been determined was less than 1,000, if 25% or more of a ZIP code’s population were enrolled in undergraduate, professional, or graduate school during the same period, or if the sampling error associated with a ZIP code’s data was deemed too high.

The sampling error was defined as too high if the coefficient of variation — a statistical assessment of how reliable an estimate is — for a ZIP code’s poverty rate was above 15% and greater than two standard deviations above the mean CV for all ZIP codes’ poverty rates. We similarly excluded ZIP codes that had a sampling error too high for their population for which poverty status had been determined, using the same definition.

The remaining 20,931 places were ranked based on their poverty rates. To break ties, we used median household income..

Additional information on the number of people living below the poverty line, median household income, and the share of households receiving SNAP (formerly food stamps) benefits are also five-year estimates from the 2019 ACS.