INDIANAPOLIS — People who buy their own health insurance have been hit lately with premium hikes that far exceed increases in premiums for employer-sponsored coverage, according to a new survey from the Kaiser Family Foundation.

The nonprofit foundation, which is separate from health insurer Kaiser Permanente, said recent premium hikes requested by insurers for individual coverage averaged 20 percent.

Some customers were able to switch plans and pay less, so people paying on their own actually wound up paying 13 percent more on average.

That tops last year's average 5 percent annual increase for employer-sponsored family coverage and almost unchanged premiums for employer-sponsored single coverage, though foundation Vice President Gary Claxton said the comparisons come with qualifications.

The individual insurance survey asked respondents for their most recent premium increases, and those can happen more or less frequently than the annual increases mostly seen in the group market, he noted.

In the online poll conducted in March and April, Kaiser queried 1,038 randomly selected people who pay for their own coverage.

Individual health insurance premiums generally rise faster than group coverage rates. They also can be affected by rising medical and drug costs and are more vulnerable when a bad economy makes healthy people drop coverage. That can leave an insurer with a higher concentration of sick people who keep coverage because they need it more and thus generate more claims.

The market also appears to be cyclical, with a big increase following a couple of years of smaller ones, said Robert Laszewski, a healthcare consultant and ex-insurance executive who wasn't involved with the study.

Guy Gooding of Sobieski, Wis., who is 59, said premiums for his and his wife's health coverage have risen 73 percent from 2007. They now pay about $646 per month, compared with $374 in 2007.

He said he has kept up with the increases because he doesn't want to sacrifice the quality of his coverage. But he'd like more of an explanation from his insurer, Anthem Blue Cross and Blue Shield.

“They're very vague on why the increases have been as much as they have been,” he said.

Insurers drew heavy criticism earlier this year after requesting premium increases of 20 percent or more from their individual customers in several different markets. Industry analysts say reports of those increases helped re-ignite the healthcare reform debate. Congress then passed in March a reform bill that aims to offer health coverage to millions of uninsured people and help people buy individual coverage through exchanges that will be launched in 2014.

About 14 million Americans under age 65 receive health insurance through the non-group or individual market, according to the foundation. In contrast, about 157 million U.S. residents get their coverage through an employer.