<P> The Loudoun County, Virginia suburb of Washington, D.C. is the highest - income county by median household income . Another Washington suburb, Arlington County, Virginia, ranks as the highest - income county by median family income . </P> <P> Many of the top counties in the following lists are found in the Northeast Megalopolis, particularly in the Washington metropolitan area and the New York metropolitan area . </P> <P> Presented below are the 25 wealthiest counties (with populations of 65,000 or greater) in the United States by median household income according to the 2012 American Community Survey prepared by the US Census Bureau . Six of the counties are located in the state of Maryland, five are in Virginia, four in New Jersey, three in New York, two in California, and one each in: Colorado, Georgia, Michigan, Tennessee, and Texas . </P> <Table> <Tr> <Th> Rank </Th> <Th> County </Th> <Th> State </Th> <Th> Median Household Income </Th> </Tr> <Tr> <Td> </Td> <Td> Loudoun County </Td> <Td> Virginia </Td> <Td> $117,876 </Td> </Tr> <Tr> <Td> </Td> <Td> Fairfax County </Td> <Td> Virginia </Td> <Td> $112,436 </Td> </Tr> <Tr> <Td> </Td> <Td> Howard County </Td> <Td> Maryland </Td> <Td> $108,844 </Td> </Tr> <Tr> <Td> </Td> <Td> Hunterdon County </Td> <Td> New Jersey </Td> <Td> $105,186 </Td> </Tr> <Tr> <Td> 5 </Td> <Td> Arlington County </Td> <Td> Virginia </Td> <Td> $100,474 </Td> </Tr> <Tr> <Td> 6 </Td> <Td> Stafford County </Td> <Td> Virginia </Td> <Td> $97,606 </Td> </Tr> <Tr> <Td> 7 </Td> <Td> Putnam County </Td> <Td> New York </Td> <Td> $96,223 </Td> </Tr> <Tr> <Td> 8 </Td> <Td> Somerset County </Td> <Td> New Jersey </Td> <Td> $95,825 </Td> </Tr> <Tr> <Td> 9 </Td> <Td> Douglas County </Td> <Td> Colorado </Td> <Td> $95,324 </Td> </Tr> <Tr> <Td> 10 </Td> <Td> Morris County </Td> <Td> New Jersey </Td> <Td> $95,294 </Td> </Tr> <Tr> <Td> 11 </Td> <Td> Montgomery County </Td> <Td> Maryland </Td> <Td> $94,965 </Td> </Tr> <Tr> <Td> 12 </Td> <Td> Prince William County </Td> <Td> Virginia </Td> <Td> $93,744 </Td> </Tr> <Tr> <Td> 13 </Td> <Td> Nassau County </Td> <Td> New York </Td> <Td> $93,214 </Td> </Tr> <Tr> <Td> 14 </Td> <Td> Santa Clara County </Td> <Td> California </Td> <Td> $91,425 </Td> </Tr> <Tr> <Td> 15 </Td> <Td> Charles County </Td> <Td> Maryland </Td> <Td> $90,880 </Td> </Tr> <Tr> <Td> 16 </Td> <Td> Williamson County </Td> <Td> Tennessee </Td> <Td> $90,759 </Td> </Tr> <Tr> <Td> 17 </Td> <Td> Marin County </Td> <Td> California </Td> <Td> $90,535 </Td> </Tr> <Tr> <Td> 18 </Td> <Td> Anne Arundel County </Td> <Td> Maryland </Td> <Td> $89,179 </Td> </Tr> <Tr> <Td> 19 </Td> <Td> Calvert County </Td> <Td> Maryland </Td> <Td> $87,449 </Td> </Tr> <Tr> <Td> 20 </Td> <Td> Sussex County </Td> <Td> New Jersey </Td> <Td> $86,625 </Td> </Tr> <Tr> <Td> 21 </Td> <Td> St. Mary's County </Td> <Td> Maryland </Td> <Td> $86,358 </Td> </Tr> <Tr> <Td> 22 </Td> <Td> Suffolk County </Td> <Td> New York </Td> <Td> $86,334 </Td> </Tr> <Tr> <Td> 23 </Td> <Td> Fort Bend County </Td> <Td> Texas </Td> <Td> $86,256 </Td> </Tr> <Tr> <Td> 24 </Td> <Td> Oakland County </Td> <Td> Michigan </Td> <Td> $86,567 </Td> </Tr> <Tr> <Td> 25 </Td> <Td> Forsyth County </Td> <Td> Georgia </Td> <Td> $85,494 </Td> </Tr> </Table>

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