The most recent data for internal migration is obtained from the Internal Revenue Service. The IRS keep track of the number of individual income tax returns which, in a 2-year period, filed in one county in the first year and another county in the second year.

Most migration both to and from Westchester is movement within the New York Metropolitan Area. 74.5% of inmigrant returns, representing returns filed elsewhere in 2015 and filed in Westchester in 2016, were filed somewhere else in the Metro Area. The counties with the largest share of inmigrants were the Bronx (29.5%) and Manhattan (20.5%), followed by Brooklyn (9%) and Queens (8.6%).

Outmigrants are slightly more geographically disbursed, but well over half—59.2%—migrate elsewhere in the Metro Area as well, with 18.4% leaving for Manhattan, 17.6% for the Bronx, and 15.8% going to Fairfield County. Putnam and Brooklyn account for 7.4% and 6.2% of outmigrants, respectively.

Outside of the Metro Area, the State of Florida has by far the largest share of any state of outmigrants at 28.7%. Other top non-Metro Area sources and destinations include the large counties that contain Los Angeles, Chicago, and suburbs of Boston.

Domestic Migration Flow into Westchester County
Domestic Migration Flow out of Westchester County