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Arizona is rejoining a children's health insurance program for low and middle-income families, becoming the last state in the union to provide coverage for health care, dental care, speech therapy and other services to families who don't qualify for Medicaid.

The Centers for Medicare and Medicaid Services announced Monday that it had approved Arizona's plan to unfreeze enrollment in the Children's Health Insurance Program (CHIP), effective Tuesday. The insurance program, funded jointly by the state and federal governments, covers children up to age 18 whose families earn too much to qualify for Medicaid but don't have their own health insurance.

The state estimates that 30,000 to 40,000 children will become newly eligible for health coverage as a result of the decision. The children will gain access to a variety of health services starting Sept. 1. The state froze the rolls for its program, known as KidsCare, in 2009 to save money in the wake of the recession, which hit Arizona particularly hard. That was before the 2010 Affordable Care Act prohibited states from reducing children's health coverage. The program was formally shut down in 2014.

Arizona Gov. Doug Ducey (R) signed legislation in May that restored access to the program.

A 2014 study by Georgetown University researchers concluded that Arizona families who were forced to switch from the KidsCare program to private insurance sold through the marketplace likely paid more and received fewer benefits. At the time, Congress was considering an end to federal funding for CHIP, which covers about 8 million children.

Daniel Scarpinato, a spokesman for Ducey, said because the federal government picks up the cost of the program until certain limits are reached, Arizona will pay nothing to rejoin CHIP. The federal government will pay about $4.7 million to cover 30,000 to 40,000 children in the first year of the program.

The decision enabled the state to "do something really positive for families in our state and do it in a fiscally responsible way," Scarpinato said. Rejoining CHIP is "not impacting our bottom line. It doesn't require a tax increase or impact other programs."