Meanwhile, as many as 1 million Californians who buy individual policies are having their coverage discontinued despite President Barack Obama's promise that it wouldn't happen.
If healthy people avoid buying insurance on the exchanges, it will undermine insurers' business models and ultimately force premiums higher.
If those signing up trend to the elderly and sickly "your insurance is going to cost more and that will discourage those younger people from coming in," warned Lisa Folberg, a vice president with the California Medical Association. "There's still a lot of enrollment and outreach work that needs to be done."
Wednesday's Health and Human Services report provided the first glimpse into enrollment operations at Covered California, which faces a monumental task to reach millions of people without insurance and sway them to sign up under the federal Affordable Care Act.
The report, covering the start of open enrollment on Oct. 1 through Nov. 2, also showed that about 80,000 lower-income people would be eligible for expanded Medicaid coverage under another prong of the overhaul.