For nearly a decade, the Silicon Valley enclave of Atherton reigned as the most expensive ZIP code in America. This year, it was dethroned – by a private island off the coast of Miami.
According to a new report from real estate data firm PropertyShark, Miami Beach’s Fisher Island (33109) claimed the nation’s top spot in 2025 with a median sale price of $9.5 million, a 65% jump from last year.
That bump ended Atherton’s eight-year streak at No. 1, though the San Mateo County community still logged a record $8.33 million median, good for second place nationwide.
“Price trends were so vertical on Fisher Island this year that the cheapest home sold for $1.41 million, while the most expensive was bought for nearly $23.7 million,” PropertyShark reported.
An aerial view of Atherton. For the first time in nearly a decade, Atherton has lost its title as America’s most expensive ZIP code, but California remains the nation’s luxury housing powerhouse. (Noah Berger/Special to The Chronicle)
Atherton, a small, largely residential town between Menlo Park and Redwood City, is defined by acre-plus lots and zoning that limits most parcels to a single home, keeping supply tight.
The housing stock skews to gated estates and new-build compounds, aided by a streamlined permitting process. It attracts high-profile buyers – including Warriors star Stephen Curry, Netscape co-founder Marc Andreessen, and other Silicon Valley business executives – who pay for privacy, scale and proximity to Stanford and Sand Hill Road.
Even with the shake-up at the top, California remains the undisputed capital of luxury housing.
The state accounted for 61% of the country’s 100 priciest ZIP codes and eight of the top ten, including elite coastal enclaves like Newport Beach, Santa Barbara, Stinson Beach and Los Altos, according to PropertyShark.
Newport Beach was named the most expensive city overall, with all six of its ZIP codes ranking among the nation’s top 100.
Atherton’s Council Chambers, located at 80 Fair Oaks Lane. For the first time in nearly a decade, Atherton has lost its title as America’s most expensive ZIP code, but California remains the nation’s luxury housing powerhouse. (Yalonda M. James/The Chronicle)
In the Bay Area, the luxury map is shifting but remains dense.
The region held 32 of the nation’s most expensive ZIPs, down from its pre-pandemic peak of 55. Stinson Beach in Marin County broke into the top 10 with a median of $5.23 million, marking a 38% year-over-year jump – the strongest gain in the Bay Area this year. Los Altos (94022) joined the elite tier for the first time, hitting $5.1 million.
San Francisco, however, continues to cool.
The city now has just one ZIP code on the list – 94123, covering the Marina and Cow Hollow – a steep drop from 13 in 2019.
PropertyShark’s analysis was based on closed residential sales between Jan. 1 and Sept. 30, 2025, in states where sale prices are publicly disclosed. Year-over-year comparisons rely on 2024 data covering the same nine-month period.
Top 10 most expensive U.S. ZIP codes, 2025
1. Miami Beach, Fl. – $9.5 million
2. Atherton – $8.33 million
3. Sagaponack, NY – $5.93 million
4. Newport Beach – $5.72 million
5. Water Mill, NY – $5.5 million
6. Santa Barbara – $5.24 million
7. Stinson Beach – $5.23 million
8. Newport Beach – $5.19 million
9. Los Altos – $5.1 million
9. Newport Beach – $5.1 million
10. Rancho Santa Fe – $4.99 million
This article originally published at California dominates America’s richest ZIPs, even as this Bay Area enclave loses top spot.