The 2008 Employer Health Benefits Survey conducted by the Kaiser Family Foundation and the Health Research & Educational Trust said the cost is more than double what the average worker paid nine years ago.

The findings were published online in the journal Health Affairs.

The report said many workers are also facing higher deductibles, including 18 percent with general plan deductibles of at least $1,000. Kaiser said the higher deductibles are partly driven by growth in consumer-directed plans such as Health Savings Accounts. Workers in Preferred Provider Organizations have seen their average deductible rise to $560 in 2008, up nearly $100 from 2007.

"With rising deductibles, more and more people face a substantial amount out of pocket for their health care before their insurance fully kicks in," Kaiser President and Chief Executive Officer Drew Altman said in a release.