A report from Georgetown University found that 13.2 percent of Arizona's children don't have insurance.
The new study, carried by the university's Health Policy Institute's Center for Children and Families, examined the percentage and number of uninsured children in the U.S.
The study said more states are showing increased coverage for kids. However, in Arizona it is eroding.
These findings put Arizona in third place on the list of highest percentage of uninsured children in the nation. Nevada has the highest rate of uninsured kids at 16.6 percent, followed by Alaska at 13.9 percent.
Nearly 6,000 Arizona children lost coverage between 2010 and 2012, according to the study.
Dana Wolfe Naimark, president and CEO of the advocacy group Children’s Action Alliance, said Arizona was the only state to freeze KidsCare, a program that offers insurance to children of working-poor families.
"Arizona had a really solid…program for many years," she said. "And (in 2010 the state) put a freeze on new enrollment, so no new children can get on and the enrollment dwindles over time."
In 2010, the state not only halted enrollment in KidsCare, but also stopped covering childless adults under the state's Medicaid program in an effort to balance Arizona's budget.
Wolfe Naimark said she expects more children to get coverage under the Affordable Care Act, which expanded the state's Medicaid program, and set up the online federal marketplace where people can purchase health insurance.