California's health insurance exchange led the nation in enrollments during its inaugural month of operation, but the 35,000 tentative sign-ups represent just a fraction of the eventual goal.

Covered California aims to sign-up as many as 2.2 million people by the end of next year, either in private insurance coverage or Medicaid services for the needy.

The figures released Wednesday by the U.S. Department of Health and Human Services did not disclose demographic details, but Covered California officials said those seeking coverage in the state during the first month of open enrollment were generally older and had previously been denied coverage.

California Medical Association vice president Lisa Folberg warns that if those signing up trend to the elderly and sickly, insurance will cost more and that will discourage younger people from signing up.