The justices let stand a federal appeals court ruling that upheld the Fed's cap of about 24 cents per transaction on so-called "swipe fees." That ruling was a setback for merchants who pay the fees to banks every time a customer uses a debit card to make a payment.
The case was a battle between two powerful and politically influential industries with billions of dollars at stake.
Retailers pay the fees to banks every time a customer uses a debit card to make a payment. Swipe fees are supposed to cover the banks' costs for providing the service.
The fee cap set by the Fed in 2011 currently averages about 24 cents per transaction. Before the cap was imposed, fees averaged 44 cents per swipe.
A federal judge struck down the cap last year, agreeing with merchants that the Fed improperly including data that made the cap too high. But the U.S. Appeals Court for the District of Columbia overturned that decision in a win for the banks. That decision will stand now that the high court declined to intervene.
Congress mandated a ceiling on debit-card swipe fees as part of 2010 legislation passed in response to the financial crisis. The Fed had initially proposed a 12-cent fee limit, but retailers argued that the Fed was influenced to double that level under pressure from bank lobbyists.
Retailers said the Fed deviated from the 2010 law's intent by having the cap include bank expenses that the law doesn't allow. The appeals court rejected that argument, deferring to the Fed's "reasonable interpretation" of the law.
The Fed rule doesn't apply to credit cards, government-issued debit cards, prepaid cards or cards issued by banks and credit unions with assets under $10 billion.
Richard Hunt, president and CEO of the Consumer Bankers Association, praised the high court for refusing to hear the case and said consumers should come first, "not the bottom line of retailers."
But Mallory Duncan, senior vice-president and general counsel of the National Retail Federation, said retailers would continue to press the issue in the courts over the "anti-consumer and anti-competitive practices of the card industry."