The cost of health insurance coverage provided by nonfederal public and private employers increased nearly three times as fast this year as it did last year, with up to one-third of the increase attributable to the 2010 federal healthcare law, according to a national survey.

The 13th annual survey by the Kaiser Family Foundation and the Health Research & Educational Trust found that in 2011 the average annual premiums for individual coverage were $5,429, or 8% higher than in 2010, and premiums for family coverage were $15,073, or 9% higher. The rise in the cost of family coverage was a sharp acceleration from the 3% increase the same survey found in 2010.

The only factor among many possible drivers to the latest premium increase that the survey authors were able to quantify were two provisions of the Patient Protection and Affordable Care Act that went into effect last year: a requirement for plans to offer coverage to the young adult offspring of their enrollees and mandated coverage of preventive care. Those provisions composed up to 2 percentage points of the 9% increase, the authors found in a separate analysis.

“Clearly, there has been an impact,” said Gary Claxton, a vice president for Kaiser and co-executive director of the Kaiser Initiative on Health Reform and Private Insurance, about the federal law.