There are at present two inconsistencies with respect to the sharing of personal health information (PHI) among health care professionals caring for a patient whom the information concerns. First, there is an inconsistency between what is in theory the ethics and law governing the confidentiality and privacy of this information--it may only be disclosed with informed consent--and what is the actual practice of health care professionals--they share it without such consent. Second, there is an inconsistency between what ethics and law demand in theory and what all parties want: They all approve of the current practice. Ethics and law can be brought into line with what is needed to act in the patient's best interests and with what people want, without opening up any serious potential for abuse of privacy and confidentiality, by establishing a safeguarded, provision-of-care exception that allows co-caring health care professionals to share patients' PHI. The requirements for a system establishing such safeguards are proposed. The basic governing presumption is respect for the person and for rights to autonomy, self-determination, privacy, and confidentiality. Therefore, disclosure may only be made with the informed consent of the competent person to whom the information pertains, unless a defence of necessity applies. Where there is doubt about someone's competence, there should likewise be doubt about disclosure without that person's informed consent. Where the person is incompetent, such a disclosure can be made to the patient's substitute decision makers, most often the family, if that is necessary for the care of the patient and in the patient's best interests. To the extent possible, consistent with the best interests of the patient, the wishes of incompetent people should be respected.