Flashbulb memories are vivid and salient memories for the moment one hears about a surprising, emotional, and significant event. The current research examined flashbulb memories for a loved one's medical diagnosis, focusing on individual and situational factors associated with memory development and endurance over time. An online survey collected memory narratives and subjective ratings from 309 mothers who received a diagnosis of Down syndrome for their child. Time since diagnosis ranged from 1 month to 52 years. Using two independent measures, the Flashbulb Memory Checklist and the Autobiographical Memory Questionnaire, we found that a majority of diagnosis memories qualified as flashbulb memories, even 20 years or more after the event. Importantly, support from the medical staff at diagnosis emerged as a critical variable related to flashbulb memory development and the persistence of these flashbulb memories over time.