Mass casualty incidents (MCI), particularly involving pediatric patients, are high-risk, low-frequency occurrences that require exceptional emergency arrangements and advanced preparation. In the aftermath of an MCI, it is essential for medical personnel to accurately and promptly triage patients according to their acuity and urgency for care. As first responders bring patients from the field to the hospital, medical personnel are responsible for prompt secondary triage of these patients to appropriately delegate hospital resources. The JumpSTART triage algorithm (a variation of the Simple Triage and Rapid Treatment, or START, triage system) was originally designed for prehospital triage by prehospital providers but can also be used for secondary triage in the emergency department setting. This technical report describes a novel simulation-based curriculum for pediatric emergency medicine residents, fellows, and attendings involving the secondary triage of patients in the aftermath of an MCI in the emergency department. This curriculum highlights the importance of the JumpSTART triage algorithm and how to effectively implement it in the MCI setting.