(CNSNews.com) – The four richest counties in the United States, when measured by median household income, are all suburbs of Washington, D.C., according to newly released data from the Census Bureau.

They are Loudoun County, Va., where the median household income was $125,900 in 2015; Falls Church City, Va., where it was $122,092; Fairfax County, Va., where it was $112,844; and Howard County, Md., where it was $110,224.

The Census Bureau treats independent cities such as Falls Church, Va., as the equivalent of a county when calculating its median household income statistics.

Note: Read our discussion guidelines before commenting.