Among the working-age population, ages 18 to 65, poverty rose to 12.9 percent up from 11.7 percent in 2008 -- the highest rate among the working-age since the 1960s.
Other findings released today show one in five American children now live in poverty, and one in four blacks and Hispanics live in poverty.
Experts say the report is unlikely to spur immediate policy changes or new government initiatives to help the poor and won't carry much sway with voters in November.
"Poverty is not as big an issue right now as middle-class unemployment. That's a lot more salient politically right now," said Lawrence M. Mead, a New York University political science professor.
"I'd say poverty is not on the agenda of the nation as a whole and there's a lot more discussion right now on whether we should be raising taxes or not," said Danzinger.
ABC News' Maya Srikrishnan and the Associated Press contributed to this report.