Welfare caseloads rose in 23 of the 30 largest states, which comprise 88 percent of the nation's population, for the year ending in March, said the analysis conducted by The Wall Street Journal and the National Conference of State Legislatures.
Early in the recession, welfare cases rose slowly and fell in some states, the Journal said, but now more people are resorting to the government checks as their unemployment benefits run out.
The increase marks the first since then-President Bill Clinton pledged to "end welfare as we know it" through legislation he signed in 1996.
Welfare cases had hit a high of about 5 million in 1995, then declined sharply with the law that limited benefits to five years, with some exceptions, and stressed getting welfare recipients into jobs. The number of families on welfare was at 1.6 million in September, the most recent date for which national tallies are available.
Among individual states, Oregon's total was up 27 percent in May from a year earlier, while South Carolina had a 23 percent increase. California had a 10 percent jump in the year ending in March.
In recent months, New York has had a 1.2 percent increase, Illinois a 3 percent jump and Wisconsin 3.9 percent.
Welfare rolls are falling in Michigan and New Jersey.
The expansion of welfare rolls signals the system is working as it should at a time of increased need, some experts said.
"To me, it's good news," says the Brookings Institution's Ron Haskins, who helped draft the 1996 welfare-overhaul law as a Republican congressional staff member. "This is exactly what should happen."