Family medical histories play an invaluable role in disease prevention, diagnosis and treatment. Self reported medical histories frequently contain incorrect or incomplete information, severely diminishing the quality of care and clinical outcome of the patient. While tools for obtaining and analyzing medical histories are available to medical professionals, no system exists to allow families to actively participate in the collection and utilization of medical history data. We have developed a free web-based service (http://www.inherithealth.com) that allows a family to collaboratively capture and store medical history information relevant to breast cancer. The service is built on a custom framework that enables the integration of existing breast cancer risk assessment models with web-based software to communicate evidence-based risk assessment to consumers. Preliminary user evaluations indicate that consumers find the tool usable, and are interested in learning about their breast cancer risk.