A new report by California's online health insurance marketplace shows 30,000 people enrolled for policies under the federal health care reforms in October, most of them older.
The pace of enrollments has been accelerating since then.
The report released Thursday by Covered California, which operates the online exchange, shows that 56 percent of the 30,830 people who had enrolled in plans by Oct. 31 were in the 45- to 64-year-old category.
Just 23 percent were age 18 to 34, a younger and typically healthier demographic that insurers say they need to make the policies financially viable.
Executive Director Peter Lee said that balance had been expected in the early days of the exchange, as people with pre-existing conditions who had no previous insurance flocked to the site.
Enrollees are defined as those who have selected an insurance policy but may not yet have actually paid for it.