CSG Midwest
According to the National Institute for Early Education Research, 18 states had at least 30 percent of 4-year-olds enrolled in state-funded preschool as of 2016. That compares to only two states in 2002. In the Midwest, Wisconsin and Iowa have the highest rates. (Nationally, only Florida and Oklahoma rank ahead of Wisconsin.)
The Wisconsin Constitution calls for schools to be “free and without charge for tuition to all children between the ages of 4 and 20 years,” and local districts receive state dollars for 4-year-old kindergarten via the K-12 funding formula (aid is equivalent to 0.5 or 0.6 dollars per child). Nearly all of Wisconsin’s school districts now provide voluntary, universal kindergarten to 4-year-olds.
Iowa also is among the nine U.S. states that provide districts with preschool dollars via their K-12 funding formulas, according to the Education Commission of the States. School districts in Iowa receive foundation aid based on their enrollment count for 4-year-olds (50 percent per child). The number of children served through Iowa’s preschool program has more than quadrupled since its inception in 2007, with about 98 percent of the state’s school districts now participating.
CSG Midwest
Thousands of 4-year-olds in Minnesota are attending prekindergarten classes this fall as the result of a $25 million investment made by the Legislature. With this money, the state targets aid for school districts and charter schools that serve high numbers of low-income students as well as areas with limited access to high-quality prekindergarten programs.

The 2011-12 school year was a difficult one for pre-K advocates as state funding fell and after a decade of growth, pre-K enrollment stalled.

An estimated 16,000 additional 4-year-olds in Michigan will be able to enroll in preschool next year under a budget enacted by the legislature.  Governor Rick Snyder is set to sign into law his proposal to increase funding for preschool in his 2013 budget request by 60 percent.  Snyder’s 2013 budget includes $65 million more for The Early Start Readiness Program. He reportedly plans to seek an additional $65 in the 2014 state budget to expand pre-k services further. 

U.S. Education Secretary Arne Duncan took his case for $75 billion to expand pre-kindergarten to the House Education and Workforce Committee on Tuesday. Duncan called the plan to make preschool available to more four-year-old children, "the smartest use of our education dollars.”

It is the growing consensus among education leaders that vital learning happens before age 5. Until the recent economic downturn, state funding for early childhood education had been increasing steadily. Between 2001 and 2012, funding more than doubled to $5.1 billion annually. Maryland’s funding level increased nearly 600 percent, from $19.9 million in 2005 to $113.9 million in 2012. Alabama’s pre-K funding more than quintupled during that period. Since the start of the Great Recession, some have backtracked on support for early education. According to data from the National Institute for Early Education Research, Missouri’s funding for pre-K has dwindled from $14.7 million in 2005 to $11.8 million in 2012. Arizona’s funding, which was once more than $12.5 million, has been eliminated, taking preschool services away from more than 4,300 children.

Research shows that children who attend pre-K programs are more successful in later grades. However, state funding and policies regarding pre-k programs vary widely.