"The Federal Reserve ran out of time to get enough data, now that the Fed is data dependent, to justify a June liftoff," said Michael Hanson, senior U.S. economist at Bank of America Merrill Lynch.
The minutes of the central bank's April meeting, released Wednesday, showed Fed officials believe a June rate hike is unlikely.
Many of the participants in the meeting didn't think "the data available in June would provide sufficient confirmation that the conditions for raising the target range for the federal funds rate had been satisfied," the minutes said, "although they generally did not rule out this possibility,"
"A few" members said economic data over the next month would warrant lifting short-term rates, which have remained close to zero for over six years, the Fed wrote in the minutes. The central bank slashed rates in an attempt to bolster the economy during the financial crisis of 2008.
"I don't think [the Fed] has ruled out rate hikes for the rest of the year," Hanson said. "September is still very much alive and December is a possibility if [economic data] disappoints, but June just seemed too soon."
Meanwhile, when the Fed does pull the trigger, its liftoff is likely to be small, perhaps 25 basis points. But some central bankers are worried that even a small rate hike could trigger a surge in other rates, such as the one banks pay to borrow money from the Fed itself.
Hanson said that particular concern is unlikely to prompt a further delay by the Fed. "Things have to deteriorate further for the Fed to be putting off rate hikes [in 2015]," he added.
Investors are concerned about the impact of a change since since low rates helped fueled the six-year bull market in equities, which sent the S&P 500 soaring over 200% from its March 2009 low.
When the Fed does announce higher rates, Hanson thinks the markets will see a modest selloff, but stresses the importance of how the Fed communicates its messages.
"If the Fed makes it very clear they are normalizing policy and not trying to undermine the recovery, we're not going to have a major selloff," he said. "If the Fed fumbles that message, it could be a little more ugly."