Patient presents with symptoms consistent with a diagnosis of Major Depressive Disorder, Single Episode (MDD, single episode).  The patient reports depressed mood, anhedonia, and significant weight loss over the past two months.  Clinical interview reveals diminished interest or pleasure in all or almost all activities, fatigue, feelings of worthlessness, excessive or inappropriate guilt, recurrent thoughts of death, and difficulty concentrating.  The patient denies suicidal ideation or intent but exhibits psychomotor retardation.  Symptoms are causing clinically significant distress or impairment in social, occupational, or other important areas of functioning.  These symptoms are not attributable to the physiological effects of a substance or another medical condition.  The patient does not meet criteria for a manic or hypomanic episode.  Differential diagnoses considered include adjustment disorder with depressed mood, bereavement, and medical conditions that can mimic depression.  Assessment includes a review of systems, mental status examination, and screening for substance use.  Plan includes initiation of pharmacotherapy with a selective serotonin reuptake inhibitor (SSRI) and referral to psychotherapy for cognitive behavioral therapy (CBT).  Patient education provided on medication management, potential side effects, and the importance of therapy adherence.  Follow-up appointment scheduled in two weeks to assess treatment response and adjust medication as needed.  Diagnosis codes include F32.9 (Major depressive disorder, single episode, unspecified) for ICD-10-CM.  Medical billing will reflect evaluation and management (E M) codes based on time spent and complexity of medical decision making.  Keywords: Major Depressive Disorder, MDD, Single Episode, Depression, Anhedonia, Depressed Mood, Mental Health, Psychiatry, Diagnosis, Treatment, ICD-10, F32.9, DSM-5, Psychotherapy, CBT, SSRI, Medication Management, Medical Billing, EHR, Electronic Health Records, Clinical Documentation.