Question: The ED physician performs a level-two E/M on a patient with sleep issues. The medical record indicates that the patient had obstructive sleep apnea caused by excess weight. Should I use ICD-9 code 780.51 to represent this condition? Minnesota Subscriber Answer: Code 780.51 (Insomnia with sleep apnea, unspecified) is not specific enough for your scenario. Use 780.51 when the physician cannot (or has not yet) determined the cause of the condition. Because the physician noted that excess weight caused the apnea, you should instead choose 327.23 (Obstructive sleep apnea [adult] [pediatric]) as a diagnosis. On the claim, report 99282 (Emergency department visit for the evaluation and management of a patient, which requires these three key components: an expanded problem focused history; an expanded problemfocused examination; medical decision-making of low complexity) and 327.23. Also, include 278.01 (Morbid obesity) as a secondary diagnosis to represent the cause of the patient's obstructive sleep apnea.