Spurred on by recent health care reforms and the Triple Aim's goals of improving population health outcomes, reducing health care costs, and improving the patient experience of care, emphasis on population health is increasing throughout medicine. Population health has the potential to improve patient care and health outcomes for individual patients. However, specific population health activities may not be in every patient's best interest in every circumstance, which can create ethical tensions for individual physicians and other health care professionals. Because individual medical professionals remain committed primarily to the best interests of individual patients, physicians have a unique role to play in ensuring population health supports this ethical obligation. Using widely recognized principles of medical ethics-nonmaleficence/beneficence, respect for persons, and justice-this article describes the ethical issues that may arise in contemporary population health programs and how to manage them. Attending to these principles will improve the design and implementation of population health programs and help maintain trust in the medical profession.