All 11 health insurance companies in Covered California this year will stay on for 2018, but their proposed rates average a weighted increase of 12.5%.

Silver-tier consumers may see an additional cost-sharing reduction surcharge averaging 12.4%, if the federal government does not commit to subsidizing payments through 2018. The proposed rates and the surcharge are under review.

The 11 are Anthem Blue Cross Life & Health Insurance Co., Blue Shield of California, Chinese Community Health Plan, Health Net Inc., Kaiser Permanente, L.A. Care Health Plan, Molina Healthcare Inc., Oscar Health Plan of California, Sharp Health Plan, Valley Health Plan and Western Health Advantage.

However, Anthem will remove coverage from most areas. Blue Shield's HMO will expand into Solano, Contra Costa, Alameda, and Ventura counties. Health Net is adding its PPO to region 3 in Sacramento, Placer, Yolo, Los Angeles, San Diego and other parts of Southern California, but partially removing its HMO from some regions. Oscar will expand to northeast Los Angeles.

Enrollment begins Nov. 1.