Finite Element (FE) models of Anthropomorphic Test Devices (ATD), commonly known as crash test dummies, have become popular in automotive sector for restraint development, automotive crashworthiness,occupant safety, as well as in applications for other industries. The increase in cost effectiveness of computational power in recent years has resulted in more complex and detailed computer models of ATDs with increased levels of correlation. There has been growing demand for these models due to the inherent benefits of reduced cost and time in the product development cycle.This paper highlights the development process of the highly detailed frontal impact ATD model, the Harmonized Hybrid III (HIII) 50th, in the LS-DYNA FE code, which represents the anthropometry of a 50th percentile adult male. The current work describes the advancements of this model and its customized chest feature to illustrate the predictive capabilities.The geometry, connectivity and inertial properties for the model are obtained from available drawings and hardware. The models material properties are implemented from physical test data after numerical parameter extraction and verification through coupon simulations, enabling characterization using the latest material modeling techniques. All the injury output sensors and instrumentation in these models are developed and implemented based on all possible instrumentation information in hardware.The model is then validated against a variety of component, sub-assembly, and full dummy level load cases,which is key in developing a reliable product that meets industry expectations. Selective validation cases for the neck, pelvis, lumbar and thorax are presented for the Harmonized HIII 50th, which show a high level of correlation.