Openness about sperm and egg donation and the regulation of donor anonymity or non-anonymity are new phenomena. How do affected families, clinics, and regulators deal with information about gamete donors and the donation itself? And how does this knowledge management contribute to the creation and enactment of kinship? Addressing these questions in Germany and Britain, this ethnography makes a comparative contribution to the empirical and theoretical analysis of kin-formation and social change. In (K)information, Maren Klotz presents a contemporary renegotiation of the values of privacy, information-sharing, and connectedness as they relate to the social, clinical, and regulatory management of kinship information.