Objective. Conceptually sound subscales for the Middle-Childhood Home Observation for Measurement of the Environment (MC-HOME) were created and evaluated utilizing 3 large-scale data sets including children ages 6 to 9 years: the Project on Human Development in Chicago Neighborhoods (PHDCN), Panel Study of Income Dynamics-Child Development Supplement (PSID-CDS), and the National Longitudinal Survey of Youth-Child Supplement (NLSY-CS). Design. Sample sizes were 459 children in the PHDCN, 152 children in the PSID-CDS, and 6,961 children in the NLSY-CS. We grouped items into subscales based on conceptual coherence and evaluated the reliability of the proposed subscales by examining individual item-to-scale correlations and Cronbach's alphas. We tested predictive validity by calculating correlations with cognitive and behavioral outcomes in each data set. Results. Results suggest 7 out of 9 conceptually based MC-HOME subscales are associated with children's cognitive status, even after adjustment for key demographic characteristics. In contrast, mixed results were found for children's behavioral outcomes. The Parental Warmth and Parental Lack of Hostility subscales are the most predictive of behavior problems. Conclusions. Conceptually meaningful subscales are promising to examine children's cognitive and behavioral outcomes, although more and finer-grained analyses of the ways these conceptually meaningful HOME subscales relate to children's later outcomes are needed to further validate the approach established here.