Therapist "missteps" (i.e., inadvertent, less optimal, or noncollaborative therapist behaviors) have the potential to negatively impact youth and family engagement in community mental health services. The present study explores potential misstep occurrences and whether they varied across various distal and proximal factors related to treatment planning, preparation, and clinical context. Data were drawn from a multi-site cluster-randomized controlled trial focused on promoting therapist use of evidence-informed procedures to engage youth and families in urban and rural community mental health services. Audio recordings from 391 treatment sessions delivered by 92 therapists were transcribed and coded for missteps occurrences. Missteps were sporadic, but occurred in most sessions, frequently manifesting as advice giving, but taking a variety of other forms. Their occurrence appeared to be lower when supervision involved preparing a plan for engaging the client, when there was a single participant in the session, and when treatment sessions occurred soon after supervision. Engaging in preparatory activities in supervision and receiving timely supervision prior to treatment delivery may be more protective against therapist missteps than simply selecting a practice to deliver. Additionally, unique challenges of family sessions may increase the likelihood of missteps occurring, highlighting the importance of specialized training for conducting family sessions.