More than half of the country’s 500 most expensive ZIP codes are in California, according to annual rankings from Forbes.
"In the big California markets there is essentially a chronic shortage of homes," Mike Simonsen, CEO of real estate data company Altos Research, told Forbes. "For the number of people who might want homes, there’s always an order-of-magnitude-fewer homes available than there are in Midwest, for example."
Forbes asked Altos Research to rank the median asking prices for single-family homes and condominiums in the more than 20,000 ZIP codes where it gathers data to find the 500 most expensive. Altos weighted the median home cost based on the mix of homes in the market.
Among the top 25 most expensive ZIP codes, 13 were in California, 10 were in New York (six in New York City alone), one was in New Jersey, and one was in Maryland.
The most expensive ZIP code was 91008, which contains Duarte, Calif., a northeast suburb of Los Angeles with a population of 1,391 and only 12 homes on the market. The median cost of a home in this tiny market is $4,276,462. Because of the few homes on the market, a single listing can easily drive up the median and may therefore not be representative of how everyone there lives — there’s a $19.8 million home for sale in the area right now, for example, Forbes said.
Among the top 25 priciest ZIP code areas, median listing prices ranged from $4.3 million to $2.7 million. That’s somewhat higher than the range in 2009: $4.1 million to $2.6 million, and significantly higher than the range in 2008: $3.9 million to $1.8 million.
Even so, the overall median among the 500 most expensive ZIP codes fell 5 percent this year from the same time last year, to $1.2 million. In 2009, the overall median fell 7 percent.
"We have yet to see mortgage defaults climb aggressively into higher-priced homes, but there are some signs that those could hit in next twelve months," Simonsen said. "If those mortgage resets drive inventory at the higher end, that would cause major problems."
Top 25 most expensive U.S. ZIP codes
| Rank | ZIP code | Median Home Cost |
| 1 | 91008 (Duarte, Calif.) | $4,276,462 |
| 2 | 94027 (Atherton, Calif.) | $4,010,200 |
| 3 | 90274 (Rolling Hills, Calif.) | $3,892,456 |
| 4 | 07620 (Alpine, N.J.) | $3,814,885 |
| 5 | 10014 (New York, N.Y.) | $3,785,445 |
| 6 | 90210 (Beverly Hills, Calif.) | $3,684,150 |
| 7 | 10065 (New York, N.Y.) | $3,626,001 |
| 8 | 94920 (Belvedere, Calif.) | $3,283,269 |
| 9 | 10012 (New York, N.Y.) | $3,221,371 |
| 10 | 93108 (Santa Barbara, Calif.) | $3,151,220 |
| 11 | 11568 (Old Westbury, N.Y.) | $3,110,769 |
| 12 | 10013 (New York, N.Y.) | $3,101,848 |
| 13 | 92067 (Rancho Santa Fe, Calif.) | $3,055,740 |
| 14 | 91302 (Hidden Hills, Calif.) | $3,055,538 |
| 15 | 94022 (Los Altos Hills, Calif.) | $3,048,846 |
| 16 | 92661 (Newport Beach, Calif.) | $3,036,601 |
| 17 | 11976 (Water Mill, N.Y.) | $3,006,849 |
| 18 | 94024 (Los Altos Hills, Calif.) | $2,974,058 |
| 19 | 11932 (Bridgehampton, N.Y.) | $2,959,231 |
| 20 | 94010 (Hillsborough, Calif.) | $2,948,423 |
| 21 | 11765 (Mill Neck, N.Y.) | $2,835,000 |
| 22 | 10003 (New York, N.Y.) | $2,825,587 |
| 23 | 21056 (Gibson Island, Md.) | $2,765,385 |
| 24 | 90265 (Malibu, Calif.) | $2,730,577 |
| 25 | 10021 (New York, N.Y.) | $2,671,667 |
Source: Forbes, from Altos Research data.
