The Most Ethnically Diverse ZIP Codes in America

ZIP code 94531, in Contra Costa County east of San Francisco, is 24.7 percent Black, 23.6 percent Hispanic, 23.1 percent White, and 20.7 percent Asian. Four groups, none smaller than 20% of the population, none larger than 25%. Across 16,898 ZIP codes in the country, that is about as evenly divided as American geography gets in terms of diversity.

We score every ZIP code on the CensusEasy Diversity Score, a 0 to 100 index measuring the chance that two residents picked at random are of a different race or ethnicity, using the five Census Bureau categories. The score rewards balance across groups rather than the high presence of any one particular group, and the method is on our methodology page.

The most diverse ZIP codes

*ZIP codes with at least 20,000 residents.

What the balance looks like

The scores at the top are separated by fractions of a point, so the composition matters more than the ordering.

*White, Black, and Asian figures are non-Hispanic. Other racial and multiracial groups are not shown, so percentages do not sum to 100%.

94531 in Contra Costa County has the tightest spread of any large ZIP code, with only four points separating its largest group from its smallest. 19149 in Philadelphia and 11580 in Nassau County are close behind. 96786 in Honolulu County reaches the top four by a different route, since Hawaii's population includes large Native Hawaiian and multiracial populations that the four columns above do not capture.

California and the suburbs

Six of the top twelve are in California, and none of them are in San Francisco or central Los Angeles. They are in Contra Costa and Solano counties in the outer Bay Area, in Alameda County, and in Sacramento. Two more sit in King County outside Seattle. The pattern matches what we found at the county level, where the most diverse places turned out to be large suburban counties rather than the cities they orbit, as in Gwinnett County outside Atlanta.

The East Coast entries are the ones with the longest histories. 02125 covers part of Dorchester in Boston, 19149 is in Northeast Philadelphia, and 11435 is in Queens, all neighborhoods that have absorbed successive waves of immigration for a century.

A caution about ZIP codes as geography

ZIP codes were built to deliver mail and not exactly to describe communities. They follow postal routes, they cross municipal and neighborhood lines, and the Census Bureau approximates them with ZIP Code Tabulation Areas rather than measuring the postal boundary itself. A high score tells you that a mail-delivery area contains a balanced population.

For a boundary built around communities instead, see the most ethnically diverse neighborhoods in America, which uses census tracts rolled into local neighborhood names. The larger geographies are in the most diverse cities in America, and the full list of every ZIP code is at most diverse ZIP codes.

Sources

The Diversity Score is a CensusEasy original index, a Simpson diversity index over the five race and ethnicity shares rescaled from 0 to 100, documented on our methodology page. Race, ethnicity, and population figures are from the U.S. Census Bureau American Community Survey for ZIP Code Tabulation Areas. Full ranking: most diverse ZIP codes.