IVIVE can facilitate the use of in vitro toxicity testing data in risk assessment and regulatory decision-making. In 2018, ICCVAM established an IVIVE workgroup to explore how IVIVE can best be applied to these purposes. The workgroup is sponsored by ATSDR and EPA, and currently has members from seven ICCVAM agencies. The workgroup is currently cataloging and evaluating currently available IVIVE approaches. Activities have focused on harmonizing the technical terms used in IVIVE application, evaluating their suitability for specific research or regulatory purposes, and assessing whether additional tools or models are needed. The workgroup’s findings will be reported in a publication planned for 2021 that will systematically present the best practices and encourage the judicious use of IVIVE.