Objectives (1) To examine clinician adherence to a standardized assessment battery across settings (acute hospital, inpatient rehabilitation facilities [IRFs], outpatient facility), professional disciplines (physical therapy [PT], occupational therapy, speech-language pathology), and time of assessment (admission, discharge/monthly), and (2) to evaluate how specific implementation events affected adherence. Design Retrospective cohort study. Setting Acute hospital, IRF, and outpatient facility with approximately 118 clinicians (physical therapists, occupational therapists, speech-language pathologists). Participants Participants (N=2194) with stroke who were admitted to at least 1 of the above settings. All persons with stroke underwent standardized clinical assessments. Interventions Not applicable. Main Outcome Measures Adherence to Brain Recovery Core assessment battery across settings, professional disciplines, and time. Visual inspections of 17 months of time-series data were conducted to see if the events (eg, staff meetings) increased adherence ≥5% and if so, how long the increase lasted. Results Median adherence ranged from .52 to .88 across all settings and professional disciplines. Both the acute hospital and the IRF had higher adherence than the outpatient setting (P≤.001), with PT having the highest adherence across all 3 disciplines (P<.004). Of the 25 events conducted across the 17-month period to improve adherence, 10 (40%) resulted in a ≥5% increase in adherence the following month, with 6 services (60%) maintaining their increased level of adherence for at least 1 additional month. Conclusions Actual adherence to a standardized assessment battery in clinical practice varied across settings, disciplines, and time. Specific events increased adherence 40% of the time with those gains maintained for >1 month 60% of the time.