With the inflation rate about half of the Federal Reserve's 2% target, the central bank is facing a major test and some experts wonder whether it will eventually need to ramp up its quantitative easing program. 

The Fed cut official interest rates effectively to 0 in late 2008 during the financial crisis.

Since then, it has bought more than $2.5 trillion in bonds to bolster an anemic economic recovery and speed up the decline in unemployment.