The PHR systems need to be integrated with a wide variety of healthcare IT systems including EHRs, electronic medical devices, and clinical decision support services to get their full benefit. It is not possible to sustain the integration of PHRs with other healthcare IT systems in a proprietary way; this integration has to be achieved by exploiting the promising interoperability standards and profiles. This chapter provides a survey and analysis of the interoperability standards and profiles that can be used to integrate PHRs with a variety of healthcare applications and medical data resources, including EHR systems to enable access of a patient to his own medical data generated by healthcare professionals; personal medical devices to obtain the patient's instant physiological status; and the clinical decision support services for patient-physician shared decision making.