Gaining a better understanding of the change process holds promise to improve alcohol treatment. Ecological momentary assessment (EMA) coupled with intensive longitudinal data (ILD) approaches have been proposed as promising methods that can advance change process research but have been used infrequently in AUD treatment research. The current study used these approaches to examine the within-person associations of motivation and self-efficacy and drinking among treatment seeking problem drinkers. Participants (N=96) received daily EMA surveys before, during, and after treatment for seven weeks spread over a nine month period. Multi-level modeling was used to test the within-person relationships between the change processes and drinking, controlling for between-person associations and prior drinking. Results indicated that daily fluctuations in motivation and self-efficacy significantly predicted drinking over the next 24 hours; however, several theory-driven hypotheses regarding factors that might moderate that relationship were not supported. Overall, results support the advantages of EMA and ILD as methods that can advance AUD treatment research.