Some Oregon residents could pay up to 38 percent more for health insurance next year, the latest salvo in an ongoing battle between Obamacare's supporters and opponents over premiums.

The state's insurance regulator was one of the first to finalize 2016 premium rates for the individual and small business markets, which Obamacare covers.

For the state's individual market, the final rate decisions range from an average increase of about 8 percent to nearly 38 percent, depending on the insurance company, the regulator said Friday.

The standard premium for a silver plan, the second of three Obamacare plan options, for a 40-year-old Portland resident range from $271 to $389 a month, the regulator said.

"Our final rate decisions reflect our commitment to ensuring that Oregonians can count on the coverage they purchase," said Insurance Commissioner Laura Cali in a statement.

Last month, insurers disclosed proposed 2016 rate increases for Obamacare enrollees. Under the law, an insurer must disclose any rate hikes of 10 percent or more.

Some insurers disclosed huge rate increases of 50 percent or more.

Opponents of the healthcare law pounced on the huge rate hikes, saying that it shows the law is not in fact lowering healthcare costs as originally promised.

Supporters counter that the rate hikes are still only proposed at this point and will need to be negotiated down. They point to studies that show the overall premium increases across the country will be modest at best.

For instance, one analysis from the nonpartisan Kaiser Family Foundation found that in 11 major cities the cost of a silver plan would be on average about 4 percent higher next year.