Sagaponack, Water Mill among priciest U.S. ZIP codes in which to buy a home

Two Long Island communities ranked among the top five most expensive ZIP codes to buy a home in the United States this year, according to the latest annual ranking from a national real estate data company. 

Sagaponack ranked third, with a median home sale price of $5.9 million, and Water Mill ranked fifth, at $5.5 million based on sales that closed from January to September, according to the list from PropertyShark. The data include sales of houses, condos and co-ops but exclude multi-parcel transactions.

Sagaponack’s ranking fell from No. 2 last year, while Water Mill dropped from No. 3.

The top spot for 2025 went to Miami’s Fisher Island, where the median sale fetched $9.5 million, and the cheapest home sold for $1.4 million, according to PropertyShark.

Overall, there were nine East End ZIP codes that cracked the top 100 most expensive in the country, up from eight last year. The others pricey areas were Wainscott at $4.5 million (No. 12), Amagansett at nearly $3 million (No. 36), Bridgehampton at $2.9 million (No. 39), Quogue at $2.7 million (No. 46), Fishers Island at $2.2 million (No. 85), Sag Harbor at nearly $2.2 million (No. 90) and Southampton at nearly $2.2 million (No. 91).

Two Nassau County communities landed among the top 100 this year. Old Westbury, with a median price of nearly $2.9 million ranked 40th and Manhasset, at almost $2.1 million, was No. 99.

The report accurately reflects the highest-priced areas by measuring deals that have already closed, as opposed to other national rankings that focus on a seller’s asking price, said Judi Desiderio, senior vice president at real estate brokerage William Raveis in East Hampton.

However, it misses the difference in prices between homes in Southampton and East Hampton villages and the surrounding areas because of its reliance on ZIP code-level data, said Desiderio, whose firm publishes quarterly market reports. Prices in the villages are much higher, she said.

While Sagaponack has long been one of the Hamptons' priciest areas, the rise of Water Mill on the list and the inclusion of Sag Harbor stood out, said Michael Daly, a real estate agent at Douglas Elliman in Sag Harbor.

"For years, Sag Harbor was the blue-collar [and] artists’ and writers’ area," he said.

Rising prices in Water Mill are tied to the construction of new luxury mansions both south and north of Montauk Highway, Daly said.

By Jonathan LaMantia

jonathan.lamantia@newsday.com@jonlamantia

Jonathan LaMantia covers residential real estate and other business news on Long Island. He previously covered the business of health care for Crain's New York Business.