The 10281 ZIP code, which includes the World Financial Center, holds the top spot in New York City. Work addresses are sometimes used by employees living outside the country because their employers have tax departments that assist with the multinational filings, and addresses of accountants or attorneys are also used. In 10281, 45 percent of the returns had adjusted gross incomes of $200,000 or more.

Peoria Ranking

While many of the areas with the greatest proportion of high-income tax filers are where they’d be expected -- northeast U.S. communities, suburban Chicago, Beverly Hills and other wealthy enclaves -- there are a few outliers as well.

The 61629 ZIP code in Peoria, Illinois, which includes the global headquarters for heavy equipment maker Caterpillar Inc., ranks second for proportion of tax filers with top incomes.

That’s because some employees living outside the U.S. use the company’s headquarters for their tax filings, said Caterpillar spokesman Rusty Dunn. In some cases, their incomes are inflated by reimbursements for housing cost and taxes related to their foreign assignments. As in the case of the wealthy urban zones, Peoria County backed Obama over Republican challenger Mitt Romney, 51.3 percent to 46.9 percent.

Energy Companies

A Houston ZIP code that has the highest concentration of high-income filers in the nation has a similar story. It is home to post office boxes used by energy companies and others, boosting its concentration of high incomes.

The list of ZIP codes where most of the wealthiest taxpayers are concentrated also shows the reach of higher rates would extend well beyond large metropolitan areas.

In total, there were in 2009 more than 4.1 million tax filers with adjusted gross incomes of $200,000 or more, the data shows. They were located in almost 19,000 ZIP codes.

If rates are raised, it will disproportionately hit such higher-income metropolitan areas as New York, Philadelphia, Chicago and San Francisco, where residents with those elevated earnings also typically have higher housing and other expenses.