Gull-billed Terns are at the northern extent of their range in New York and their statewide distribution is highly restricted. They are known to breed on only five marsh islands off the south coast of Long Island in Nassau County. They are threatened by habitat loss and human disturbance. Their coastal salt marsh habitat is threatened by changes to hydrological processes due to coastal development and by sea-level rise and increasing storms due to global climate change. This species is especially sensitive to human activity near nesting locations (Molina et al. 2009).

This species is so rare in New York that it is difficult to compare distribution over a limited time period. Gull-billed Terns were found in three blocks in the first Breeding Bird Atlas from 1980 to 1985 and in five in the second atlas from 2000 to 2005 (McGowan and Corwin 2008). During both atlases the species was restricted to the south shore of Long Island in Nassau County, with one record from the first atlas from nearby southwestern Suffolk County (McGowan and Corwin 2008).

Gull-billed Terns have likely always been a rare and local breeder in the state. The long-term trends are unclear. A few specimens were taken in the 1880s during the breeding season from sites where breeding is presently known or suspected (Griscom 1923, Bull 1964, McGowan and Corwin 2008). The species was likely extirpated from the state for an unknown extent of time soon after those specimens were taken (Griscom 1923, McGowan and Corwin 2008). There are only sporadic records; some associated with hurricanes during migration in the fall from 1934 to 1975 (Cruickshank 1942, McGowan and Corwin 2008). Breeding was confirmed in the state in 1975 by the discovery of a pair with a nest with eggs on South Line Island in Nassau County (Levine 1998).