Background: Recovery capital is a theoretical construct elucidating the resources that sup- port recovery from addiction. The 50-item Assessment of Recovery Capital (ARC) instrument and related brief-format versions are the predominant measures of this construct. However, some of the ARC’s psychometric properties are not well-established, particularly in racially and economically diverse populations. Objectives: We aimed to determine if the ARC is a valid and reliable measure of recovery capital in a diverse sample. Methods: Paper-and-pencil survey data were collected between March 2017 and May 2018 from a low-income, racially diverse sample of adults in recovery (N1⁄4273). Participants were recruited from nontreat- ment community settings throughout a mid-sized northeastern U.S. city. They completed the ARC and sociodemographic questions. To determine the ARC’s reliability and factor structure, we used item-level analyses and Cronbach’s alpha, followed by confirmatory and exploratory factor analyses. Results: Several items performed poorly, having means close to response extremes and problematically small variances. Cronbach’s alpha for the full meas- ure was a 1⁄4 .92; however, alphas for the majority of subscales were below .70. The a priori 10-factor model solution failed, preventing interpretation of the confirmatory factor analysis results. Exploratory factor analysis revealed that although the 10-factor model marginally fit the data, items did not load together as proposed. Not once did all five subscale items load highly on the same factor. Conclusions/Importance: The ARC has substantial weaknesses in its theoretical alignment, item performance, and psychometric properties with diverse popu- lations. We recommend the development of a new multidimensional, theory-aligned meas- ure, following a rigorous measurement development protocol.