Treat and release and treat and refer protocols or practices refer to the onsite treatment of patients by responding emergency medical services personnel that does not involve transporting patients to health care facilities for additional assessment and treatment. The goal of these protocols is to allow patients to be released from care or to be referred directly to non-emergency services by emergency medical services personnel when appropriate, diverting patients from emergency departments. One health technology assessment that included a relevant randomized controlled trial and economic evaluation and 2 non-randomized studies were identified for inclusion. These studies examined treat and release or treat and refer protocols for treating hypoglycemia and exertional heat stroke, and for attending to older people following a fall. Overall, the clinical evidence summarized in this report suggests that treat and release protocols are as good as, or better than, usual care (i.e., onsite treatment of immediate medical care followed by transportation to health care facilities). Across most reported outcomes, there were no significant differences between patients who received care using treat and release or treat and refer protocols, and those who received usual care; however, there were some instances where the use of these protocols was associated with improvements in some clinical outcomes, such as patient satisfaction, risk for future falls or fractures, and some measures of repeat access to health care services. Findings related to the cost-effectiveness of treat and refer protocols were inconclusive because of the limited generalizability of the findings from the included economic evaluation. The economic evaluation estimated that implementing a treat and refer protocol for older patients who experienced a fall did not result in significant changes to health care resource utilization and did not generate improved health-related quality of life compared to usual care. No evidence-based guidelines regarding the use of treat and release protocols for patients requiring emergency medical services were identified.