#2 Nevada – Nevada ties with Florida for the second highest rate of children lacking health insurance in the U.S. – 16 percent. And with just 22 percent of Nevada kids currently receiving Medicaid, federal help could begin to close the gap. (Photo by Charley Gallay/Getty Images)

The Supreme Court has declared that states can opt out of the provision in the Affordable Care Act that expands Medicaid coverage (at the federal government’s expense for the first three years, and with states paying a small percentage of the cost after that) to people under age 65 who reach up to 133 percent of the federal poverty level. But which states stand to lose the most if their governors say “thanks, but no thanks,” to the Medicaid funds? We ranked them based on the Kaiser Family Foundation data on the states with the highest rates of children currently being covered by Medicaid the percentage have no health insurance (via their parents or the government) at all.