Federal tax data reveal that California and New York accounted for the ten counties with the largest net losses of taxpayers to other states, underscoring a continued shift in domestic migration patterns.
The figures, compiled from federal tax returns, provide one of the clearest measures of where Americans are relocating and the income moving with them.
Economists note that these migration trends illuminate broader changes in state economies, tax bases, and housing markets as households weigh affordability, taxation, and employment.
Los Angeles County recorded the nation's largest net loss, with 17,496 tax filers departing and nearly $1.9 billion in income leaving the state.
Other significant outflows occurred in Queens County, New York, which lost 17,109 filers, and the Bronx, which lost 16,319. Orange County, California, and Suffolk County, New York, followed with losses of 11,618 and 10,434, respectively.
Manhattan presented a contrasting case, gaining more interstate tax filers than any other county while losing close to $1 billion in adjusted gross income, indicating that incoming residents earned less than those who left.
The data point to a sustained movement away from large coastal counties toward growth centers in the Sun Belt and Mountain West, including Maricopa County, Arizona, and Harris County, Texas.
Maricopa County led inbound migration with a net gain of 9,353 filers, followed by Harris County with 8,955, King County, Washington, with 8,297, and Clark County, Nevada, with 7,524.
Additional counties among the top ten for losses included San Diego, Nassau, Riverside, San Bernardino, and Kings counties, reflecting concentrated departures across both states.
Analysts attribute much of the relocation to tax burdens and regulatory conditions, with many movers selecting states that impose lower or no income taxes.
Observers warn that continued departure of higher-earning residents could weaken tax revenue in affected states, particularly where proposed policies call for increased taxation on top incomes.
California retains one of the highest top marginal income tax rates in the country, keeping the state central to discussions over the fiscal impact of outmigration.
