Consumer prices unexpectedly fell 0.2% in March from the previous month.
Economists were predicting a flat reading.
Excluding food and energy, prices were up 0.1% (economists were looking for a 0.2% advance).
Year over year, consumer prices were up 1.5% (versus 1.6% expected and 2.0% in February), and prices excluding food and energy were up 1.9% (versus 2.0% expected and 2.0% in February).