Summary: Nearly two-thirds of Americans under 65--some 150 million people--have employment-based private health insurance. At the same time, the percentage of Americans who are uninsured or rely on Medicaid, particularly children, continues to increase. GAO found that as costs for providing health insurance increase, the percentage of Americans under age 65 with private health insurance coverage decreased from 75 percent in 1989 to about 71 percent in 1995. Of this general decline, about 70 to 90 percent was due to fewer working-age adults and children being covered as dependents. Between 1989 and 1995, the percentage of working-age adults (18 to 64 years old) with private insurance coverage deceased from 76 percent to 73 percent. If the same percentage of working-age adults had been covered in 1995 as in 1989, about 5 million more adults would have had private insurance. However, children experienced the greatest loss of private coverage. Over these 6 years, the percentage of children under 18 with private health insurance decreased from more than 73 percent to 66 percent. If private coverage had not decreased, about 5 million more children would have private insurance.