CPI increased 0.5%, the most in three months, versus 0.1% in the prior month; on a core basis, it was up 0.4% (versus 0.3%). Both were in line with estimates. On an annual basis, CPI increased 6.4% from the year-ago period versus 6.5% in December, higher than forecasts.

Aside from the headline numbers, analysts and markets were also looking at the so-called super-core figure, or core services minus housing. It's a category that Federal Reserve Chair Jerome Powell has singled as a must-watch. That showed some easing, increasing at a slower 0.27% pace in the month and 6.2% from the prior year.

Housing contributed the most to the monthly increase in CPI, making up nearly half the gain. Food, gasoline and natural gas also boosted the monthly figure.

Where does this leave the Fed?