Although the pediatric hospitalist model system is being widely disseminated, its value in improving clinical outcomes or controlling health care costs remains to be demonstrated. The findings in studies of pediatric or adult hospitalists have been mixed, and almost all studies have been of low quality, mostly retrospective before and after comparisons subject to a variety of biases. With the necessity to restrain health care spending, the funding required from Medicaid and other 3rd-party payers to develop and sustain high-quality pediatric hospitalists services may not be forthcoming unless they are shown to improve outcomes with acceptable or reduced costs.