The Nurse Practitioner scope of practice encompasses four core competencies: advanced health assessment (comprehensive physical examination, history taking, interpretation of diagnostic data), diagnosis formulation (developing and refining differential diagnoses using clinical reasoning), therapeutic management (prescribing pharmacological and non-pharmacological interventions, ordering and interpreting diagnostic tests), and health promotion/disease prevention (screening, immunization, lifestyle counseling, chronic disease management). NPs function as autonomous primary care or acute care providers with full prescriptive authority in many jurisdictions. The scope is defined by education (graduate-level nursing program), certification (national certification examination), regulatory authority (state/provincial practice acts), and institutional privileges. NPs practice using a nursing model that integrates medical diagnostic and therapeutic knowledge with holistic patient-centered care, health promotion, and collaborative practice. The NP must distinguish between scope of practice (what the law allows), standards of practice (what the profession expects), and personal competency (what the individual NP is trained and competent to do) — the most restrictive of these three defines the boundary of acceptable practice.