For Christine and Donald Kriescher of New Franken, Wis., that has meant getting guardianship papers in order as their son Nick, 19, who is severely retarded and suffers from obsessive-compulsive disorder, approaches adulthood. And they'll need a power of attorney to help guide 20-year-old daughter Kandy, who has mild cognitive disabilities, into new programs next year when she leaves school.

In addition, the Krieschers plan to redo their will and set up a special-needs trust to transfer their insurance and savings to care for the children after their deaths.

"I will die a happy person if I can find a way so they can live and be happy and be productive, too," Christine Kriescher said. Kriescher, who is 42, added: "Putting things in place gives you peace of mind."

The U.S. Census Bureau estimates that more than one in 10 Americans between the ages of 16 and 64 suffers from some physical, mental or emotional impairment. Finding the right services — and arranging future financial support — for them can be tricky because parents can't risk jeopardizing a disabled person's public benefits.

Many of the disabled qualify for government-sponsored care or training programs. They also can get financial help through the Supplemental Security Income program, which provides a monthly allowance and generally ensures that the disabled person is eligible for important Medicaid health benefits.

But that assistance could be cut off if parents or well-meaning grandparents give a few thousand dollars to a disabled grandchild, unwittingly making them ineligible for SSI and healthcare because their assets surpass the $2,000 limit, according to the ARC of the United States, a national organization based in Silver Spring, Md., for the mentally and developmentally disabled.

A growing number of insurance and brokerage houses have set up units focused on financial planning for special-needs children, including help in setting up wills and trusts that don't threaten a child's benefits.