Expect to pay more in 2018 if you get health insurance through your employer in Pittsburgh,

Average health insurance rates for Pittsburgh-area employers are expected to rise between 6 percent and 8 percent next year — double the national average in 2017 — as the cost of medical services outpaces national projections and the region’s dominant insurers battle for market share.

Highmark and UPMC Health Plan are each offering plans that include tiered provider networks and price locks for new and renewing groups starting in January, insurance brokers say. The competition between the two carriers began heating up in July, said Tom Finneran, vice president of sales at Mount Washington-based brokerage Tucker, Johnston & Smelzer Inc.

“I didn’t expect it to be as aggressive this year,” Mr. Finneran said. “We don’t see the other carriers being so aggressive.”

But don’t expect the intense regional competition to shrink rates offered to employers, brokers agree.

And employees, both in Pittsburgh and nationally, aren’t likely to see cuts in the amount they contribute to cover health insurance. Businesses are continuing to shift health benefit costs to employees, the “primary fallback cost-containment strategy,” Kaiser Family Foundation President and CEO Drew Altman said.

Menlo Park, Calif.-based Kaiser released its annual employee-sponsored health insurance survey Tuesday, which showed employer premiums rose just 3 percent nationally in 2017 while the sum employees contribute toward health care rose sharply.

“About 30 percent of Americans report problems paying medical bills,” Mr. Altman said. “If this is the new normal, it’s not a normal that people are happy about.”

By comparison, Affordable Care Act health insurance rates were up 20 percent this year.

Nationwide, 55 percent of workers are covered by health plans offered by their companies, about the same as the 2016 rate, Kaiser said. About 151 million Americans have employer-sponsored health insurance. The average annual premiums for employer-sponsored health insurance were $6,690 for individual coverage and $18,764 for a family, according to Kaiser, while the share of the bill that workers pick up has been rising sharply. It was up to $5,714 in 2017 — a 32 percent increase from $4,316 in 2012 — for family coverage.

Workers at firms with fewer than 200 workers contribute more to their health care benefits —

$6,814 on average. Local market figures were not disclosed.

The cost of legacy health insurance coverage based on employees’ medical history can be a fraction of Affordable Care Act-compliant plans, said Dave Scott, vice president of Bethel Parkbased ARMS Insurance Group LLC.

“For medically underwritten plans, the rate increases are extremely small,” he said. “But medical costs are just climbing, and the employers have no other choice but to increase the amount the employees are kicking in.”

Highmark and UPMC each estimate that medical costs will rise 7 percent next year. Nationally, Arlington, Va.-based Pricewaterhouse Coopers Health Research Institute projects a 6.5 percent increase in the cost of a hospital stay and other medical services — the first uptick in three years.

For employer groups with at least 51 workers, UPMC Health Plan is offering to cap rates for the first year of coverage or renewal at 6 percent and 8 percent for the second year. Highmark also is offering fixed rate increases for select groups.

“Employers want high quality, but they want it to be affordable,” said Tony Benevento, senior vice president, regional markets at Highmark. “We’re working with hospital systems across the state and we’re seeing some very good results.”

For the 2018 open enrollment period that opens Oct. 1 for plans that renew Jan. 1, Highmark is pressing the idea of high performance health care networks, with plans tailored to steer employees to low cost, high quality doctors and hospitals. Such networks have been set up in Johnstown, Indiana and elsewhere.

Kim Cepullio, president of UPMC Health Plan, said UPMC has its own take on high performance networks comprising UPMC’s own and community hospitals. “We’re really looking at the employer groups, trying to find lower cost alternatives to engage at the member level,” Ms. Cepullio said.

The sting of employer insurance cost-shifting can be felt in another way: Most employers offer insurance with caps on out-of-pocket expenses, but for 27.1 million workers, the cap exceeds $6,000 a year, a sixyear high.