Pierce County employees may have to help pay for their health insurance for the first time as the county tries to balance its budget and address rising insurance costs.

Deputy County Executive Kevin Phelps told the County Council at a study session Tuesday that premiums for medical, dental and vision insurance are expected to increase about 15 percent next year, or about $5.3 million.

With some exceptions, the county in the past has covered the entire cost of insurance for employees. But with the county already looking to cut millions of dollars in spending to balance next year’s budget, Phelps said the county likely can’t absorb next year’s price hike.

In an interview, Phelps said the county might require employees to pay health insurance premiums for the first time. Alternatively, it could change the insurance plans to provide less coverage.

Phelps said county officials are looking at a tiered premium system that would treat single employees differently than married employees and employees with children.

Any changes would have to be negotiated with unions representing county employees. Phelps was to meet this afternoon with representatives of more than 20 unions to begin discussing employee benefits for 2010.

Phelps said Pierce County is “behind the curve” on charging employees for health insurance. He said most other governments already require employees to share the cost.

“Whatever we come up with, we need to come up with a way to mitigate the 15 percent increase on the premium,” Phelps said.