North Carolina’s largest insurer is hiking its premium rates on the state’s Obamacare exchange by over 13 percent.

Blue Cross Blue Shield of North Carolina said in a conference call they’ll be upping the price of their individual Obamacare-compliant plans by 13.5 percent on average for 315,000 people, according to The Associated Press. Company officials emphasized that some customers will be eligible for taxpayer subsidies on the exchange.

“It is important for customers to understand their health care needs, update their information to get the subsidy amount they are eligible to receive and select an insurance plan with the level of coverage they want at a price that works for them and their family,” said Patrick Getzen, the company’s vice president and chief actuary.

Blue Cross Blue Shield in North Carolina is continuing to sell individual health care plans that aren’t compliant with Obamacare regulations as well, which is pushing the price of its Obamacare premiums up. The old, grandfathered individual policies — sold outside the exchange — will have premium hikes of 13.4 percent. The company is hiking rates on newer, Obamacare-compliant policies by 19.2 percent on average.

“There needs to be a mix of customers within each category to balance risk and expected costs,” Getzen said.

Because healthier, previously insured people tended to keep their original health care plans, Blue Cross said its Obamacare customers were sicker and costlier to insure on average. The company has been predicting this effect all year. (RELATED: North Carolina Obamacare Insurer: Older, Sicker Mix Than Expected May Hike Premiums)

“Not as many of the state’s young and healthy enrolled as expected,” the company said in a press release this May. Just 25 percent of Blue Cross Blue Shield’s initial Obamacare sign-ups in North Carolina (to say nothing of the number than paid and continued their coverage) were between the ages of 18 and 34.

Not all of North Carolina’s Obamacare insurers have revealed their premium rates for the upcoming open enrollment period in November. The Obama administration runs the state’s exchange through HealthCare.gov and has refused to reveal premium prices until after the November midterm elections. (RELATED: Admin Won’t Release HealthCare.gov Premiums Until After Elections)

The hikes may play a role in the contest for North Carolina’s Senate seat. Sitting Democratic Sen. Kay Hagan, who voted to pass Obamacare, is fighting to keep her seat in November against Republican challenger Thom Tillis, the state Speaker of the House. Tillis has attacked Hagan over her Obamacare support in light of rising premiums and cancelled policies.

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