The headline index of prices fell 0.4% in April from the previous month, more than the 0.3% decline predicted by economists.
That marks the first back-to-back decline in monthly prices since late 2008.
Excluding food and energy, prices rose 0.1%. Economists were looking for a 0.2% increase.
On a year-over-year basis, prices rose 1.1% in April, missing expectations for a 1.3% advance.
Stripping food and energy out of the calculation, prices rose 1.7% year over year in April, missing estimates for a 1.8% rise.
More From Business Insider
- INITIAL JOBLESS CLAIMS SURGE TO 360K
- Larry Page Surprises Crowd With Candid Q&A Session Following Google's Developer Keynote
- US INDUSTRIAL PRODUCTION FALLS MORE THAN EXPECTED