 The MATCH trial will use a cluster randomization design involving 6 primary care clinics at Group Health. Of these 6 clinics, 3 will be randomized to receive Group Healths standard training in the use of Group Health back pain guidelines and 3 clinics will receive this standard training plus supplemental training. Primary care clinicians and physical therapists in the intervention group will receive training in the use of the STarTBack risk stratification strategy for matching the most appropriate evidence-based treatments to the needs of patients in each risk level. We will evaluate the effect of this supplemental training on patient outcomes, clinician and physical therapist knowledge and comfort treating patients with back pain, and utilization of services for back pain. 