Children and youth who have intellectual disabilities or developmental disorders are at elevated risk for co-occurring psychiatric or behavioral problems. These young people pose a serious challenge for administrators, program directors and clinicians, especially when they present with aggressive or disruptive behaviors. When appropriate community services have not been organized, these youth can be among the most difficult and costly to serve. Across the country, their families report relentless stress, partly because it is very difficult to obtain the help they need. This paper provides resources and strategies that have improved outcomes and lowered costs, while diminishing risk for institutional placements, referrals to juvenile justice and child welfare.