America's wealthiest ZIP codes turn up not only in those big coastal states where rich people are known to hang, but also in some surprising places in between.

Bloomberg has come up with the top 20 ZIP codes by analyzing 2015 tax data, specifically the averages for adjusted gross income. That's a taxpayer's total earnings minus deductions.

Which ZIP code is richest of all? Hint: It's not Beverly Hills 90210!

Follow along as we count down to No. 1. Median home values data is from Zillow.

20. 06831 (Greenwich, Connecticut)

Greenwich, Connecticut, mansion
Realtor.com
Greenwich is filled with estates, like this.

Average income: $626,200

This small affluent town at the southwestern tip of Connecticut is home to many hedge funds and investment houses including AQR Capital, Blue Harbor Group, Interactive Brokers, North Street Capital and Silver Point Capital.

Leafy Greenwich is considered a New York City bedroom community — midtown Manhattan is just 35 miles away. The median home value here is about $1.6 million.

Wealthy residents of Greenwich can enjoy their leisure time at one of the many country clubs and exclusive golf courses in this ZIP code.

How much home can you afford?

19. 60022 (Glencoe, Illinois)

GLENCOE, ILLINOIS/USA - MAY 9, 2017: Rows of crabapple trees in full blossom provide a luminous canopy over a curved path on a spring afternoon at Chicago Botanic Garden.
Ken Schulze / Shutterstock
The beautiful Chicago Botanic Garden lies within Glencoe.

Average income: $633,700

Nestled on the shore of Lake Michigan north of Chicago, Glencoe is a sleepy suburb with a very wealthy citizenry. The median home value is $950,000.

Glencoe has a very strict zoning code (Illinois' first) that dates back to 1921. Famed architect Frank Lloyd Wright designed many homes in this primarily residential area.

It's a common setting for films about affluent suburban life. Ferris Bueller’s Day Off and Risky Business were both set in this tony community.

18. 11568 (Old Westbury, New York)

Old Westbury, New York - July 3, 2015: Long Island Gold Coast Mansion.
Victoria Lipov / Shutterstock
Old Westbury has many historic mansions.

Average income: $639,800

Old Westbury lies in the heart of Long Island, about 30 miles east of midtown Manhattan. The median home value is $2.3 million.

The village is home to hundreds of wealthy businesspeople, athletes and entertainers. It’s also where you find the longest-running polo club in the United States, Meadow Brook Polo Club.

Residents of this wealthy ZIP code can enjoy golf, polo and a wide range of other activities favored by the affluent.

17. 06878 (Riverside, Connecticut)

Greenwich, CT, USA October 27, 2013 An adult man baits his line to fish along the Greenwich, Connecticut waterfront in fall
James Kirkikis / Shutterstock
Riverside is a waterfront community along Long Island Sound.

Average income: $661,500

Located within the town of Greenwich, Riverside is a waterfront community (on Long Island Sound) with a population of 8,400, according to the 2010 census.

NBC Today co-host Kathie Lee Gifford lives here, and so do NHL and NFL players, socialites and business magnates.

The median home value in Riverside is more than $1.5 million.

16. 98039 (Medina, Washington)

Medina, Washington USA Aerial View at Sunset Reflection on Lake, Meydenbauer Bay
Cascade Creatives / Shutterstock
Medina is on a peninsula outside Seattle.

Average income: $691,800

Medina is a wealthy enclave on the edge of a peninsula about 8 miles from downtown Seattle. The town connects to Seattle via the Evergreen Floating Point Bridge, the longest of its type in the world.

Medina is home to several of the region's business titans, including Bill Gates and Amazon's Jeff Bezos. The late Jeffrey Brotman, co-founder of the Costco wholesale club chain, also lived here.

The town is named after the city of Medina in Saudi Arabia. The median home value is $2.6 million.

15. 34102 (Naples, Florida)

Naples coastline, Florida aerial view.
pisaphotography / Shutterstock
Naples is a tony community on the Gulf of Mexico.

Average income: $694,700

Naples lies on the Gulf side of the Florida peninsula, about two hours northwest of Miami. The city is full of canals, coves, rivers and other waterways — perfect for boating or lounging by the water.

Many famous wealthy Americans are reported to have homes in the area, including "Judge Judy" Sheindlin and Fox News' Sean Hannity. The median home value here is $600,000.

The beauty of the ocean and palm trees provide a stunning backdrop for Naples' shoreline mansions and villas.

Relocating? Calculate your monthly mortgage payment.

14. 83014 (Moose Wilson Road, Wyoming)

Autumn on the Moose-Wilson Road in the Grand Teton Natioanl Park, Wyoming.
Sharon Day / Shutterstock
Moose Wilson Road is within view of the Grand Tetons.

Average income: $699,200

South of Yellowstone and Grand Teton National Parks, Moose Wilson Road is an area of Wilson, Wyoming, in the foothills of the Grand Teton mountain range.

The relatively secluded area is a popular destination for outdoorsy millionaires and billionaires.

As of 2016, the estimated population was under 4,000. Home values data is not available.

13. 94028 (Portola Valley, California)

PORTOLA VALLEY, CA - JUNE 06: Riders and their horses at the Open Horse Show competition on June 06, 2010 at Spring Down Equestrian Center in Portola Valley, CA
Anatoliy Lukich / Shutterstock
The Spring Down Equestrian Center is found in Portola Valley, California.

Average income: $701,200

Located in San Mateo County just west of Mountain View, Portola Valley is home to many tech executives and entrepreneurs. The headquarters for Tesla and Google are a short drive from the lush green acres of Portola Valley.

The late country music singer Tennessee Ernie Ford lived here, and the horse shows at the Spring Down Equestrian Center are a popular local attraction.

Homes in the middle of the pack are valued at $3.5 million.

12. 02110 (Boston)

Aerial view of Boston, MA, USA
Richard Cavalleri / Shutterstock
The 02110 ZIP code includes prime waterfront areas.

Average income: $711,900

The only urban ZIP code in the eastern United States to make the top 20 is in Boston and includes the city's waterfront and financial district.

Thanks to attractions such as the Boston Tea Party Museum and the Sargent's Wharf, addresses in the eastern shore area of downtown are coveted by both businesses and wealthy homebuyers.

The median value of a condo or single-family home within this ZIP code is just over $1 million.

11. (Far Hills, New Jersey)

Chestnut mare horse galloping in dappled sunlight. Vivid colors. Side view. Blurred action shot. Far Hills, New Jersey
Donna A. Herrmann / Shutterstock
Far Hills is in the heart of New Jersey's horse country.

Average income: $747,200

Located about 35 miles west of New York City, Far Hills is a wealthy borough in Somerset County. This ZIP code is home to the US Golf Association and the Far Hills Races, the site of the Breeders' Cup steeplechase races.

One of the largest estates in Far Hills is Natirar, a 490-acre property formerly owned by the King of Morocco.

The median home value here is just under $1 million.

10. 94111 (San Francisco)

San Francisco Skyline
Gang Liu / Shutterstock
ZIP code 94111 includes the San Francisco waterfront and financial district.

Average income: $776,400

The wealthiest ZIP code in San Francisco includes the Embarcadero area and the financial district on the northeastern edge of downtown.

Here, you can dine in splendor at the famous 1898 Ferry Building on the waterfront and then catch a ferry to Oakland or Alameda across the bay.

The iconic Transamerica Pyramid is a major landmark within this ultra-upscale ZIP code. The median home value is about $1.2 million.

9. 02493 (Weston, Massachusetts)

Weston, Massachusetts - July 11, 2015:  The historic Georgian 1768 Golden Ball Tavern, now fully restored and operated as a colonial-era museum
LEE SNIDER PHOTO IMAGES / Shutterstock
Weston is home to Colonial American historic sites, like the Golden Ball Tavern, built in 1768.

Average income: $860,400

It takes a big paycheck to live in this sleepy suburb west of Boston. Weston has been a popular choice for athletes and executives from the Boston area, due to its low population density, low crime rate and large lots.

Hockey great Bobby Orr lives here, and NBA Hall of Famer John Havlicek had a home in Weston. The median home value is about $1.5 million.

Weston was a dry town — meaning no alcohol sales permitted — until fairly recently. The ban wasn't lifted until 2008!

8. 60043 (Kenilworth, Illinois)

The Hiram Baldwin House in Kenilworth (1905). The Frank Lloyd Wright design is similar to the
Teemu008 / Flickr
The Frank Lloyd Wright-designed Hiram Baldwin House is in Kenilworth.

Average income: $861,000

North of Chicago along the shore of Lake Michigan, Kenilworth is a planned community with many wealthy residents. It is the richest zip code in the U.S. Midwest.

A local attraction is the Hiram Baldwin House, designed by Frank Lloyd Wright and built in 1905. The median value of all homes in the area is $1.3 million.

Just south of the community is the campus of elite Northwestern University.

7. 90067 (Century City, California)

Century City skyscrapers sit near Los Angeles in early 2015. Construction had just begun on renovating the mall, including one of the skyscrapers on the far left.
Johnny Habell / Shutterstock
Century City has many skyscrapers.

Average income: $905,700

This community, developed on the former backlot of 20th Century Fox, lies between Beverly Hills and West Los Angeles.

Currently home to Fox Studios and the Westfield Century City mall, Century City is a wealthy enclave of relatively small households, with an average of just 1.9 residents per home.

The Census reports Century City has a significant population of Iranian-born residents: 21% of those surveyed. The median home value is just over $1 million.

6. 19035 (Gladwyne, Pennsylvania)

A typical estate in Gladwyne
Realtor.com
Gladwyne is filled with impressive mansions.

Average income: $957,200

Northeast of Philadelphia, the Gladwyne ZIP code is a favorite among local luminaries in the fields of art, science, entertainment and sports.

NBA Hall of Famer Allen Iverson reportedly lives here, and Los Angeles Dodgers infielder Chase Utley used to. The median value of a single-family home or condo in this suburban area is just shy of $1 million.

Gladwyne boasts significant natural beauty including the Henry Foundation botanic gardens and Rolling Hill Park, a historic 102-acre park.

5. 10577 (Purchase, New York)

Purchase, NY, USA May 12, 2008 Jean Dubuffet's Kiosque l'evide graces the landscaped grounds of Pepsi Cola's world headquarters
James Kirkikis / Shutterstock
A sculpture garden graces the grounds of PepsiCo's world headquarters in Purchase.

Average income: $976,200

Sitting between White Plains, New York, and Greenwich, Connecticut, the hamlet of Purchase makes up the wealthiest ZIP code in the northeastern United States.

This quiet New York City suburb is home to the headquarters to MasterCard and PepsiCo, and it's the former hometown of Texaco and computer maker Lenovo.

The compact community has not one not two but three exclusive country clubs: Blind Brook, Old Oaks and Century. Homes in the middle of the market are valued at $1.5 million.

4. 94301 (Palo Alto, California)

Palo Alto, CA/USA - circa June 2011: Streets of Palo Alto, California
amadeustx / Shutterstock
Palo Alto has many examples of Spanish architecture.

Average income: $1.18 million

This Silicon Valley ZIP code encompasses downtown Palo Alto, old Palo Alto and Crescent Park. The median home value here is an impressive $3.8 million.

Many of the world’s richest tech entrepreneurs and executives live in the area, and the ZIP code is where many of the industry's best-known companies got their start. For example, Facebook originally leased space in downtown Palo Alto.

Stanford University is just one ZIP code over.

3. 33480 (Palm Beach, Florida)

Palm Beach, Fl., November 19, 2016:  President Donald Trump is expected to vacation at his Mar-a-Lago club and mansion in Florida.
FloridaStock / Shutterstock
Palm Beach includes President Donald Trump's Mar-a-Lago resort.

Average income: $1.25 million

Palm Beach is a narrow strip of shoreline that has long been a favorite winter address among the famously wealthy.

President Donald Trump's has put Palm Beach in the spotlight with his frequent trips to his Mar-a-Lago resort. Other distinguished denizens of the island include singer Jimmy Buffett, talk-show host Rush Limbaugh and rocker Rod Stewart.

The median home value in Palm Beach is $640,000.

2. 94027 (Atherton, California)

A modern house in Atherton
Realtor.com
This modern house in Atherton was recently put on the market for $29.8 million.

Average income: $1.5 million

This wealthy community near Palo Alto is one of only three cities in the San Francisco Bay Area with more registered Republicans than Democrats. (Hillsborough and Danville are the other two.)

The town is home to many business giants, including investor Charles Schwab and former eBay and Hewlett-Packard CEO Meg Whitman.

Only the mega-rich can afford to live here. The median value of a home in Atherton is a staggering $6.7 million!

1. 33109 (Fisher Island, Florida)

Aerial view of Fisher Island, Miami, Florida, USA
Richard Cavalleri / Shutterstock
There's no bridge to ultra-exclusive Fisher Island.

Average income: $2.54 million

This small, secluded island community off the coast of Miami represents America's richest ZIP code, according to the Bloomberg analysis.

For 20 years in the mid-20th century, the island was owned by William Kissam Vanderbilt II — of the New York Vanderbilts. Recent residents reportedly have included Oprah Winfrey and tennis greats Andre Agassi and Boris Becker.

Fisher Island is accessible only by ferry, water taxi or personal yacht and has just 218 households. No data is available on median home values.

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