This article seeks to fill a gap in the existing nursing literature by answering the question, “Where does health policy come from?” Nursing leaders agree that nurses should be involved in developing health policy, yet most nurses are not engaged. Many factors contribute to nurses’ low rates of involvement, but the primary drivers is that nurses believe they lack the knowledge and skills to influence policy formulation. This article proposes a framework of the sources of health policy. We classify health policy sources as public, organizational, or professional, and provide examples. Nurses with a deeper understanding of the varied sources of health policy can enhance their political competence and more readily act in the policy domain.