The Fed decision came amid volatile trading on Wall Street as investors have been concerned with global credit markets as defaults on subprime mortgages continue to rise.
In a brief statement, the Fed said "credit conditions have become tighter" for some businesses but the economy is likely to continue to grow at a moderate pace.
"It's an academically-oriented Fed and I think they went by the textbook here, they moderated the language and changed it step-by-step," Gross said.
Gross said a gradual slowdown in the U.S. economy has been lost amid concerns regarding corporate credit and policymakers to cut rates at some point.
"The Fed needs to recognize is that at five-and-a quarter it's a restrictive rate relative to a 4% to 5% nominal GDP world," said Gross. "Ultimately, they are going to have to cut."
"The Fed needs to watch the markets but it also needs to watch the economy," he added.