Investigations into emotion dysregulation predominantly focus on ineffective strategy selection and implementation. However, little empirical attention has been given to the possibility that failure to engage in emotion regulation (ER) may also indicate emotion dysregulation, especially when the reason for not regulating suggests skill or motivational deficits. We randomly sampled ER strategy use up to six times per day for 5 weeks in 113 adults with elevated social anxiety. When participants reported not engaging in any recent ER, they indicated their reason for not regulating. Data were collected between 2018 and 2019. Participants reported not regulating in 60.9% of surveys. The most frequently endorsed reason for not regulating was “I was not experiencing any thoughts/feelings that I wanted to change,” followed by “I did not want to put in the effort,” then “I did not know what to do,” and finally, “I did not think I was capable.” After controlling for within- and between-person state affect, participants with lower trait-level social anxiety, depression, and emotion dysregulation scores were more likely to report no ER because they were not experiencing any thoughts/feelings that they wanted to change relative to the other three reasons that might reflect barriers to effective regulation. Trait-level generalized worry and alcohol use did not significantly predict between nonregulation reasons. Findings from these preregistered analyses suggest that not regulating—especially among persons higher in social anxiety, depression, and emotion dysregulation—may indicate ER skill or motivation deficits that point to opportunities for intervention. Results may not generalize to more demographically or clinically diverse samples.