The Labor Department said that unemployment rates fell in only 14 states. That's fewer than the previous month, when rates fell in 37 states. Rates were unchanged in 18 states.
Nationally, the rate rose to 8.2 percent in May from 8.1 percent in April, the first increase in almost a year. Employers added only 69,000 jobs, the fewest in 12 months.
Still, 27 states added jobs in May. California gained the most, adding 33,900. Ohio was next with 19,600.
North Carolina reported the biggest loss, shedding 16,500 jobs. It was followed by Pennsylvania, which lost nearly 10,000.
Nevada had the nation's highest unemployment rate, at 11.6 percent, followed by Rhode Island's 11 percent and California's 10.8 percent.
Washington state's employment rate for May was 8.3 percent, rising slightly from April's rate of 8.2 percent. The jobless rate for May 2011 was 9.3 percent.
North Dakota, meanwhile, reported the nation's lowest rate of 3 percent. Nebraska had the next lowest, at 3.9 percent.
Despite the slowdown in hiring in recent months, some of the hardest-hit states have seen substantial improvement in the past year.
Michigan and Nevada have both seen their unemployment rates fall 2.1 percentage points in the past 12 months. Both states still have higher unemployment rates than the national average. But Michigan's rate was 8.5 percent last month, down from 10.6 percent in May 2011.
Florida and Mississippi have seen their rates fall 2 percentage points in the past 12 months. Florida's rate was 8.6 percent, down from 10.6 percent in the same month last year. Mississippi's is 8.7 percent, down from 10.7 percent in May 2011.
Some of those declines reflect more hiring. The nation has gained more than 1 million jobs in the past six months.
But the lower rates also are a result of more people becoming discouraged and dropping out of the work force. The government only counts people as unemployed if they are actively looking for work.