Nassau County, NY

Nassau County, New York, a core county of the New York-Newark, NY-NJ-CT-PA market, holds $96.3B in deposits across 32 insured institutions and 338 branches. JPMorgan Chase Bank, National Association is the largest deposit holder at 22.8% share. The top three banks hold 52% of deposits, which places the county in the Moderate band. Deposits have grown 7.6% since 2020 while the branch count fell by 16.3%. It produces $100.7B of output, ranking #47 of the 1,523 ranked counties by economic output.

Ranks show where the county stands among the 1,523 ranked counties (those within a Combined or Metropolitan Statistical Area that have a branch). They describe relative position, not a rating of market quality or suitability.

Deposit trend

Branches: 404 in 2020 to 338 in 2025. Institutions: 35 to 32. Top-three share: 48% to 52%.

Institutions by deposits

The 32 insured institutions with a branch presence in this county, per the FDIC Summary of Deposits, June 30, 2025. Five-year change compares the same institution’s county deposits in 2020 and 2025. Institutions are tracked by FDIC certificate number, and where an institution acquired another bank, the acquired bank’s prior deposits are folded into the baseline so the change reflects the combined, continuing franchise rather than reading as new. “No 2020 presence” means neither the institution nor a bank it later absorbed reported deposits in this county that year. Deposit figures are nominal and are not adjusted for inflation.

Part of the New York-Newark market

Nassau County is one of 30 counties that make up the New York-Newark, NY-NJ-CT-PA market, a Combined Statistical Area (ranked #1 of 293 U.S. markets by economic output). It produces 4.7% of the market’s output and holds 3.3% of its deposits.

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