(Bloomberg) -- Health care plan premiums will rise an average of4.2 percent next year in California’s insurance exchange, thelargest Obamacare market in the U.S., state officials said.

The increase is considered low by officials at CoveredCalifornia, the authority that runs the state’s exchange, who saidmany customers would see a decrease or no change. Californians sawpremium increases this year, the first year plans were availableunder Covered California and other exchanges, that averaged as muchas 88 percent, according to the state insurance department.

Premiums for health plans under the Patient Protection andAffordable Care Act loom as a key issue in 2014 congressionalelections and are a practical concern for insurers. Large premium increases risk chasing off the healthycustomers needed to balance the cost of covering the sick.

“We have changed the trend for health-care costs,” Peter Lee,the executive director of Covered California, said today at a newsconference.

About 1.4 million people signed up for private plans in CoveredCalifornia by mid-April, more than in any other state, according tothe U.S. government. Ninety percent of those customers receivedsubsidies to reduce their premium, Lee said.

The premiums for the four largest plans in the state increased this year an average of 22 percent to 88percent compared with 2013, Dave Jones, the insurancecommissioner, said July 29.

Plan requirements

The 2014 plans were required for the first time to meet theAffordable Care Act known as Obamacare, which forced insurers tocover anyone regardless of their health, limited what they cancharge older people and mandated a package of basic benefitsincluding prescription drugs and maternity care. While thosepolicies expanded access to insurance to people who previouslywould have been denied coverage or charged prohibitive prices, theygenerally increased premiums for healthy people, insurers say.

Jones is promoting a ballot initiative that would give him thepower to reject insurers’ rate increases. Consumer WatchdogCampaign, an advocacy group that also supports the initiative,called Proposition 45, said insurers may have tempered theirincreases for 2015 in part because of the campaign.

“With health insurance companies facing Proposition 45’saccountability on the ballot, they agreed to much smaller ratehikes than those endured by consumers in 2014,” Jamie Court,president of the group, said in a statement.

Customer pool

Lee disagreed, saying he believes insurers proposed lowincreases because the Covered California customer pool isattractive.

“They want to be priced to get enrollment,” he said. He calledJones’ report “misleading and distracting.”

Ten insurers will sell plans in Covered California next year,the authority said, including WellPoint Inc. The Indianapolis-basedcompany, the second-biggest U.S. health insurer, said on Twitterthat its average increase in 2015 in California is a “modest” 5.8percent.

“Extremely happy to be part of a sustainable & affordableexchange,” the company said in its tweet.

California rates vary widely among insurers and regions of thestate. In Los Angeles County, for example, Kaiser Permanente willreduce its rates by as much as 9 percent, while WellPoint’s Anthembrand is raising rates as much as 11 percent, according to a reportfrom Covered California.

Also read:

• 2015 ratesexpected to fluctuate wildly
• Brokers say premiums are skyrocketing

Copyright 2018 Bloomberg. All rightsreserved. This material may not be published, broadcast, rewritten,or redistributed.