Gov. Scott Walker is proposing switching to a self-insurance system in 2018. He made the proposal in the state budget he delivered to the Republican-controlled Legislature on Wednesday. Under a self-insurance system, the state would pay for benefits directly for about 250,000 state workers and family members instead of purchasing insurance from 17 HMOs. The Group Insurance Board oversees the $1.5 billion state employee insurance program. It recommended making the change just hours before Walker put it in his budget. Walker estimates it will save $60 million over the next two years.