Arizona had 159,117 cases of unpaid child support at the end of May.

The total overdue came to more than $1.7 billion.

That's according to the state's Department of Economic Security, which mandates that single parents pursue child support to qualify for cash assistance.

However, many parents don't, writing off the potential aid. Often, they fear their former partner or figure the help won't be worth the stress of continued contact. In some cases, they figure there's no way their ex would be able or willing to pay.

There's something to that logic.

Recent Health and Human Services Department studies in child-support trends have found that about 10 percent of debtors owe more than $10,000, and nearly three-quarters of that group report less than $10,000 in income a year.

People in that income bracket piled up about 70 percent of state arrears, which - in Arizona, as in most states - regularly accumulate interest.

The "high debtors" were more likely to have multiple child-support orders, interstate orders and an order that had been in effect for at least 10 years.

In matching income data to debt, researchers found that about a quarter of debtors were either disabled or incarcerated.

The tally for Pima County arrears on May 31 came to more than $240,000 stemming from more than 24,600 cases.

Contact reporter Carli Brosseau at or 573-4197. On Twitter: @carlibrosseau