This article presents a new model, generated through applied theory-building research methods, that helps human resource development (HRD) practitioners evaluate the return on investment (ROI) of organization development (OD) interventions. This model, called organization development human-capital accounting system (ODHCAS), identifies return-on-investment measures for each of the elements of the human-capital employment life cycle that are impacted by OD interventions. We illustrate an application of the new model by using work/life (w/l) interventions as a test of the model. The contribution of this new model is fourfold: (1) It fills a gap in the literature by suggesting a holistic ROI framework for typically nonfinancial OD-type interventions; (2) It is generated from an accepted applied theory-building methodology; (3) It offers decision makers methods to develop hard evidence on which to evaluate w/l interventions; and (4) It has the future potential to be expanded and used to evaluate the ROI for multiple types of OD interventions. (Contains 2 tables and 2 figures.)