The figure does not include enrollment in state-based exchanges.
According to the report, 20% of such individuals did not know they were infected with HIV.
Three federal agencies say the practice violates restrictions in place under Health Insurance Portability and Accountability Act and the Public Health Service Act.
Forms to renew Medicaid and CHIP coverage are too complex, advocates say.
The measure includes a plan to eliminate the contentious "two-midnight" payment rule.