Given the current demands of the healthcare environment, a clear sense of the unique contributions of nursing to patients' outcomes is critical. This paper articulates a model that describes nursing practice on the basis of the needs and characteristics of patients. The model was developed by the American Association of Critical-Care Nurses Certification Corporation to link certified practice to patients' outcomes. The fundamental premise of this model, known as the Synergy Model, is that patients' characteristics drive nurses' competencies. When patients' characteristics and nurses' competencies match and synergize, outcomes for the patient are optimal. This paper presents the major tenets of the Synergy Model: patients' characteristics of concern to nurses, nurses' competencies important to patients, and patients' outcomes that result when patients' characteristics and nurses' competencies are mutually enhancing. By creating safe passage for patients, nurses make a significant contribution to the quality of patients' care, containment of costs, and patients' outcomes. Although the Synergy Model will be used as a blueprint for the certification of acute and critical care nurses, it is conceptually relevant to the entire profession. Dissemination of this model may help situate nursing within the current healthcare environment and facilitate intradisciplinary dialogue.