In the outpatient setting, thefirst-listed diagnosisis the condition chiefly responsible for the services provided during the encounter. Here, the stated reason for the visit iscontinued confusion and poor memory, and the provider specifically evaluates the patient’scurrent mental stateand references neurology consultation notes—actions that directly support assessment of a cognitive disorder. While HTN, GERD, and Parkinson’s are also addressed and may be reportable if they meet encounter relevance (e.g., monitored, evaluated, assessed/managed, or treated), they are not the primary driver for today’s visit based on the presenting complaint. Outpatient documentation and coding guidance emphasizes sequencing the diagnosis that best explains the visit’s main purpose first, with additional coexisting conditions listed afterward when they impact care. Since “dementia” is on the active problem list and aligns with the patient’s cognitive symptoms and the physician’s mental-status evaluation, it is the most appropriate first-listed diagnosis among the options.