The aim of this study was to identify factors contributing to clinician time spent in non-reimbursable activity on an inpatient pediatric consultation-liaison (C-L) service. A retrospective study was conducted using inpatient C-L service data on 1,246 consecutive referrals. For this patient population, the strongest predictor of level of non-reimbursable clinical activity was illness chronicity and the number of contacts with C-L service clinicians during their hospital stay. Patients with acute life-threatening illnesses required the highest mean amount of non-reimbursable service activity. On average, 28 % of total clinician time in completing a hospital consultation was spent in non-reimbursable activity. Effective C-L services require a proportion of time spent in non-reimbursable clinical activity, such as liaison and coordinating care with other providers. Identifying referral and systemic factors contributing to non-reimbursable activity can provide insight into budgeting/negotiating for institutional support for essential clinical and non-clinical functions in providing competent quality patient care.