November 22, 2004 Sources of Health and Mental Health Insurance This appendix reviews the major sources of mental health insurance in the United States, as well as recent research on each source. The review begins with private, employer-sponsored insurance and extends to public sources of mental health insurance. Sources of insurance are presented in order of the number of covered individuals.A. Employer-Sponsored Plans Nearly half the U.S. population is covered by employer-sponsored health insurance. The General Accounting Office (GAO) (2000a) found that a large majority of employers provide mental health insurance, but they impose . . .