Question: What ICD-10 code should I report for physician-documented lumbago with sciatica? Rhode Island Subscriber Answer: You must first check the medical documentation to see on which side of the patient’s body the symptoms occurred. For lumbago with sciatica on the right side, report M54.41 (Lumbago with sciatica, right side). For the same symptoms on the left side, you should report code M54.42 (Lumbago with sciatica, left side). When your physician does not document which side the symptoms were present, you should report code M54.40 (Lumbago with sciatica, unspecified side).