The need to develop measures that tap into constructs of interest to social work, refine existing measures, and ensure that measures function adequately across diverse populations of interest is critical. Item response theory (IRT) is a modern measurement approach that is increasingly seen as an essential tool in a number of allied professions. IRT-based measurement uses a model-based approach that has several analytical and explanatory advantages over classical test theory. In particular, IRT-based techniques facilitate the process of specific item selection, allow for increased measurement precision with fewer items, and provide greater capacity for understanding and accounting for measurement bias across diverse populations. A survey of the top (as rated by impact factor) 20 social work journals revealed that few measurement articles in the social work literature use IRT or other modern measurement approaches. The benefit of incorporating more IRT-based approaches for developing, refining, and ensuring the application of measures to diverse populations is discussed.