The wealthiest ZIP codes in Massachusetts are concentrated in one area, according to a recent report by the Boston Business Journal.

The report says all 10 of the state's richest ZIP codes are all within 10 miles of downtown Boston.

"A lot of people kind of think that wealth primarily lives outside the city, but in fact, the No. 1 ZIP code on the list is in Back Bay," Business Journal reporter Maya Shavit told CBS News Boston. "The Greater Boston area has some of the wealthiest pockets of Massachusetts." 

The median home value in top-ranked 02116 is $1.3 million, the report says. 

Second on the list was 02118 in the South End, which The Business Journal noted also has a poverty rate of more than 24%. Coming in third was 02446 in Brookline.

The Business Journal's report was based on income, home values and other data collected from the U.S. Census Bureau and Zillow. It found that the Top 10 wealthiest ZIP codes had a typical home value of $880,000, which is about double the national average.

"Boston continues to be a really expensive place to live, and that's no surprise to anybody," Shavit said. 

Wealthy millennials

Shavit said one of the "really surprising" findings from the research was that the median age of those in the wealthiest ZIP codes was about 35 years old.

"These millennials, these young families, these generations are kind of taking over these new areas and there's this new wave of wealth that's happening in Boston," she said.

Top 10 wealthiest ZIP codes in Massachusetts

According to the Business Journal's research, the wealthiest ZIP codes in Massachusetts are:

1. 02116 (Boston, Back Bay)
2. 02118 (Boston, South End)
3. 02446 (Brookline)
4. 02144 (Somerville)
5. 02129 (Charlestown)
6. 02140 (Cambridge)
7. 02127 (South Boston)
8. 02476 (Arlington)
9. 02139 (Cambridge)
10. 02141 (Cambridge)

Outside of Boston, a recent Realtor.com report found that Massachusetts is home two of the "hottest" ZIP codes in the country for homebuyers - Beverly and Leominster.