Expect Fed rate hikes next summer: Pimco's Mather

While the Federal Reserve did not take its first step toward raising interest rates on Wednesday, as some had expected it would, Pimco's Scott Mather wasn't too surprised.

Mather told CNBC he believes the central bank will move slowly and will likely raise rates sometime around the summer of 2015.

"The Fed's been pretty clear if you look at their messaging," Mather, Pimco's chief investment officer of U.S. core strategies, said Wednesday in an interview with "Street Signs."

"They think the summer, perhaps June is appropriate, but maybe it's later in the year, maybe it's end of summer, but that's got to be the base case from where they lift off unless there's a dramatic change in the economic outlook."

Read MoreYellen puts off rate hikes, stocks rally

The Federal Reserve building.
Andrew Harrer | Bloomberg | Getty Images
The Federal Reserve building.

Critics have complained that the Fed's statement on Wednesday was confusing because it kept in the key phrase "considerable period" when referring to how long it intends to keep short-term interest rates near zero. However, it also added a new word—saying it would be "patient" in determining when to raise rates.

Mather thinks the Fed is actually clearer now that it was a year ago.

"They've talked about the sequencing, what they'll do when they begin raising rates. They've basically outlined the time frame," he said.

"Nothing has really changed about the fundamental outlook other than the energy prices and it's probably safe to say that's what caused them to maybe slow down versus what others were expecting."

Read MoreWhat bothers me the most in Fed statement

Mather was also not surprised that there wasn't more of a focus on foreign risk in the statement.

"The Fed's mandate is domestic activity and they're setting monetary policy with that in mind," he said.

"It takes very large movements in foreign economic activity to have a real impact on the U.S. economy."