Five years into the U.S. economic expansion, inflation shows little sign of picking up as prices rise more slowly for goods and services from automobiles to medical care, complicating the Federal Reserve's drive to guide the economy away from the precipice of deflation.

The personal consumption expenditures price index, minus food and energy costs, rose 1.2 percent in 2013, matching 2009 as the smallest gain since 1955. Of 27 categories of goods and services in the gauge, 18 showed smaller price increases over the past two years, according to data compiled by Bloomberg.

The slowdown has been broad-based, with durable goods such as autos, nondurables like clothing and services including health care all playing a role. Fed policy makers are on guard to keep such disinflation from morphing into outright deflation, a persistent drop in prices that prompts households to delay purchases in anticipation of even lower costs and leads companies to postpone investment and hiring.