Health insurers intend to charge an average of 13.2 percent more for Covered California exchange coverage in 2017 than they are charging this year.
Consumers who were willing to change plans may be able to cut their own premiums an average of 1.2 percent.
Managers of Covered California, California's state-based Affordable Care Act exchange, have published those figures in a guide to proposed exchange plan premiums for 2017.
A year ago, exchange managers were predicting 2016 premiums would rise an average of 4 percent, and that consumers who were will to change plans could cut their premiums by an average of 4.5 percent.
About 90 percent of Covered California's 1.4 million customers use ACA premium tax credit subsidies to pay for coverage. The exchange did not give an estimate of what enrollees' average change in net, subsidizedpremium costs might be.
ACA regulators tie subsidy levels to the cost of the second cheapest silver plan, or plan with mid-level benefits, in a market. Exchange managers expect the average premium for the second cheapest silver plan to rise 8.1 percent in 2017. A year ago, Covered California was expecting 2016 second-cheapest silver plan prices to be 1.8 percent higher than 2015 prices.
The average cost of bare-bones bronze plan coverage is on track to rise 3.9 percent. A year ago, exchange managers were predicted bronze-level coverage costs would rise 3.3 percent in 2016.
Exchange managers say the end of a temporary ACA reinsurance program, which has been helping insurers cover the cost of individual health catastrophic claims submitted in 2014, 2015 and 2016, accounts for about 4 percentage points to 7 percentage points of the average increase. Without that change, the average increase might have been only about 6 percent to 9 percent.
Consumers have 60 days to comment on the proposed rates. California regulators have the ability to review rates and ask for changes, but they do not have the ability to reject or change rates.