New York City has long been considered the playground of America's millionaires and billionaires. But as many of the city's high earners start families and seek more space, they move out to the suburbs surrounding the city.

Stephen Higley, a professor emeritus of urban social geography at the University of Montevallo, recently ranked the richest neighborhoods in the U.S. based on American Community Survey 2006 - 2010 data.

He aggregated contiguous block groups (subdivisions of Census tracts) with a mean income over $200,000. You can read his complete methodology here.

These are the wealthiest neighborhoods in the suburbs outside of New York City — Westchester County, Long Island, Connecticut, and New Jersey.