IMPORTANCE: Elderly patients often share control of their personal health information and decision making with family and friends when needed. Patient portals can help with information sharing, but concerns about privacy and autonomy of elderly patients remain. Health systems that implement patient portals would benefit from guidance about how best to implement access to portals for caregivers of elderly patients.OBJECTIVE: To identify how patients older than 75 years (hereinafter, elders) and family caregivers of such patients approach sharing of health information, with the hope of applying the results to collaborative patient portals.DESIGN, SETTING, AND PARTICIPANTS: A qualitative study was conducted from October 20, 2013, to February 16, 2014, inviting participants older than 75 years (n = 30) and participants who assist a family member older than 75 years (n = 23) to 1 of 10 discussion groups. Participants were drawn from the Information Sharing Across Generations (InfoSAGE) Living Laboratory, an ongoing study of information needs of elders and families based within an academically affiliated network of senior housing in metropolitan Boston, Massachusetts. Groups were separated into elders and caregivers to allow for more detailed discussion. A professional moderator led groups using a discussion guide. Group discussions were audiotaped, transcribed, and analyzed inductively using immersion/crystallization methods for central themes.MAIN OUTCOMES AND MEASURES: Central themes regarding sharing of health information between elderly patients and family caregivers.RESULTS: Seven lessons emerged from 2 main themes. First, sharing information has consequences: (1) elders and caregivers have different perspectives on what is seen as the "burden" of information, (2) access to medical information by families can have unintended consequences, and (3) elders do not want to feel "spied on" by family. Second, control of information sharing is dynamic: (4) elders wish to retain control of decision making as long as possible, (5) transfer of control occurs gradually depending on elders' health and functional status, (6) control of information sharing and decision making should be fluid to maximize elders' autonomy, and (7) no "one-size-fits-all" approach can satisfy individuals' different preferences.CONCLUSIONS AND RELEVANCE: Information sharing and control are complex issues even under the most well-meaning circumstances. While elders may delegate control and share information with family, they want to retain granular control of their information. When using patient portals, simple proxy access may not adequately address the needs and concerns of aging patients.