Hybrid computational phantoms offer unique advantages for the construction of diverse anthropomorphic models. In this paper, a methodology is presented for the construction of patient-dependent phantoms built around anthropometric distributions of the U.S. adult and pediatric populations. The methodology relies on the flexibility of hybrid phantoms to match target anthropometric parameters as determined from National Center for Health Statistics databases. Target parameters as defined in this paper include the primary parameters such as standing height, sitting height, and total body mass; and secondary parameters such as waist, buttocks, arm, and thigh circumference. As a demonstration of this methodology, the UF hybrid adult male (UFHADM) and UF hybrid 10-year-old female (UFH10F) were selected as representative anchor phantoms for this study and were subsequently remodeled to create 25 different adult male and 15 different pediatric female patient-dependent phantoms. The phantoms were evaluated based on appearance and internal organ masses. Aesthetically, the phantoms appear correct and display characteristics of a diverse population including variability in body shape and standing/sitting height. Organ masses display several general trends, including a gradual increase with both standing height and subject weight. Selected organ masses from the UFHADM series were also compared with published correlations taken from a 2001 French-based autopsy study. The organ masses were located well within the statistical deviation presented in the autopsy study and followed similar trends when correlated with both standing height and body mass index.