New York ? Most states reimburse foster parents significantly less than the actual cost of raising a foster child, complicating the task of finding good homes for children who need them, according to a first-of-its-kind survey.

The survey analyzed regional living expenses and calculated on a state-by-state basis the minimum cost of adequately raising a foster child. Only Arizona and the District of Columbia pay foster parents more than this minimum amount, according to the survey.

To adequately cover the cost of rearing a foster child, base payments in 28 states would need to be raised at least 50 percent, and five states – Idaho, Missouri, Nebraska, Ohio and Wisconsin – would need to more than double their base rates, according to the report. It was compiled by the University of Maryland School of Social Work, the National Foster Parent Association, and Children’s Rights, a New York-based advocacy group.

Of the more than 500,000 U.S. children in foster care at any given time, about 75 percent live with foster parents, while most of the others are placed in group homes and institutions.

The report expressed concern that inadequate reimbursement rates would worsen a shortfall of foster parents, “potentially increasing the likelihood that children will be placed in institutions or shuttled from one foster placement to another.”