Individuals with cognitive deficits and their families are prime examples of collaborative "systems" that seek to perform everyday tasks together. Yet there has been little investigation into how these families communicate and coordinate in basic tasks like remembering appointments. In this paper we take a distributed cognition approach to studying ten families struggling with amnesia through nonparticipant observation and interviews. Our data show that the families work closely together as cognitive systems that must compensate for memory volatility in one of the members. We explore our participants' strategies for overcoming these difficulties and present lessons for the design of assistive technologies, highlighting the need for redundancy, easy and frequent synchronization, and awareness of updates. We conclude with implications for distributed cognition theory.