Four years after the Affordable Care Act transformed the health insurance market in Colorado, thousands of Coloradans learned Monday they might very well be on the hook for historically large health insurance premium increases come next year.

The Colorado Division of Insurance released its preliminary rate adjustment proposals Monday morning, and the figures are destined to become fodder for politicians who have been sharply critical of Obamacare’s inability to reign in health care costs.

Anthem Blue Cross and Blue Shield, for example, is seeking a 26.8% premium increase for individual plans in 2017.

Rocky Mountain HMO is seeking a 34.6% increase.

In addition, Anthem has decided not to offer its PPO (Preferred Provider Organization) individual plans in 2017. In all, the Colorado Division of Insurance said Monday around 92,000 people with individual plans from Anthem, UnitedHealth, Humana, and Rocky Mountain Health Plans will have to find other coverage during open enrollment in the fall.

“All of us in the industry must tackle the more pressing question of what is driving the increased health costs in the individual market that lead to higher premiums,” said Colorado Insurance Commissioner Marguerite Salazar in a press release.

Approximately 450,000 Coloradans get their health insurance through the individual market. More than half – or 2.8 million -- continue to get insurance through an employer.

“In general, the companies have indicated that the people enrolled in individual plans have used more healthcare services and with greater frequency than expected,” said Salazar.

Here are the proposed rate adjustments:

  • Anthem BCBS: 26.8%
  • Bright Health: New to market
  • Cigna: 9.5%
  • Colorado Choice: 36.33%
  • Denver Health: 0.08%
  • Freedom Life: 9.98%
  • Golden Rule: 40.6%
  • Kaiser Foundation Health Plan: 13.6%
  • National Foundation Life: 9.98%
  • Rocky Mountain HMO: 34.6%