Background Child care quality rating and improvement systems exist to inform child care decisions and improve the quality of care. While previous research has shown QRIS have effects on quality, less is known about how child care providers vary in engagement and improvement within QRIS. In a voluntary QRIS, it is important to understand how providers vary in motivation, engagement, and progress within the system. Objective Identify provider characteristics and attitudes that predict QRIS quality advancement. Identify and describe provider subgroups whose rates of quality improvement were different. Method A random sample of providers (N=179) and their coaches were interviewed five times over 2 years. The outcome was change in QRIS levels. Predictors were type of care, personal/professional characteristics, QRIS motivation, and coach perceptions of provider motivation and likelihood to advance. Linear regression was used to model change in QRIS level over five time points. Latent profile analysis was used to sort providers into classes. Results Significant overall predictors of QRIS change were providers’ education level and fewer years of experience, and coach’s perception of the provider’s likelihood to advance. Four subgroups in the latent profile analysis varied by rate of advancement, type of care, education, experience, professional engagement, QRIS motivation, and general readiness to change. Conclusions Results point to the importance of assessing early and continuing attitudes, engagement, professionalization, and education of participating child care providers. The incentives and needs of providers in most QRIS will vary widely. Technical support geared to provider characteristics will be more effective in improving within QRIS. (author abstract)