Demographers say that suggests eroding career opportunities and a diminished ability to buy a home. Young adults typically make long-distance moves to seek a new career, while those who make local moves often do so when buying a home.
Homeownership declined for the fifth year in the row to 63.9 percent.
"Many Americans continue to think that a rising tide lifts all boats," said Sheldon Danziger, a University of Michigan economist. "But the bad news is that given the way economic growth trickles down now, the number of poor and disadvantaged will remain high unless we do more to help those in need."
With poverty remaining high, food stamp use continued to climb. Roughly 15.8 million, or 13.6 percent of U.S. households, received food stamps, the highest level on record. Just over half of these households, or 52 percent, were below poverty and 44 percent had one or more people with a disability.
By state, Oregon led the nation in food stamp use at 20.1 percent, or 1 in 5, due in part to generous state provisions that expand food stamp eligibility to families. Oregon was followed by more rural or more economically hard-hit states, including Mississippi, Kentucky, Maine, Michigan and Tennessee. Wyoming had the fewest households on food stamps, at 7 percent.
In 45 states and the District of Columbia, poverty rates remained steady at high levels. Mississippi, the poorest state in the nation, was one of just three states posting increases, from 22.6 percent to 24.2 percent. California and New Hampshire were the others.
In Minnesota and Texas, the percentage of people in poverty declined.
Among the 25 largest metropolitan areas, the Washington, D.C., area had the highest median household income in 2012 at $88,233, followed by the San Francisco and Boston metro areas. The Tampa-St. Petersburg metro area had the lowest median house income at $44,402.
The official poverty level is based on a government calculation that includes only income before tax deductions. It excludes noncash government aid such as food stamps. Counting food stamps would have boosted 4 million people, lowering the U.S. poverty rate to 13.7 percent.