Increasingly, geographic information systems employing spatial data are being used to identify communities with poorer health care status. Since health care indicators are strongly linked to income, could these data, usually based on adult indicators, be used for pediatric health care need? We hypothesized that individual-level indicators such as quality of life scales (QOL) would be better than community-level indicators at identifying families with poorer health care practices. Surveys and medical record reviews were used for a sample of 174 caregivers of young children. Lower level of income was associated with poorer scores on several QOL domains, and on the primary health practices (i.e., non-urgent emergency room use and lack of age-appropriate immunization status). One community-level indicator, the medically underserved area (MUA), was almost as good as the best individual-level indicators at predicting primary health care practices. The community-level indicator of MUA appears to meet its initial intent, providing information on the location of very low-income individuals with high health care need even among a sample of Medicaid-insured children with an identified health care provider. (Authors)