Question: Encounter notes indicate that the provider treated a patient with a diagnosis of “thoracic neuritis/NOS/sacral and sacrococc..” I cannot find the proper ICD-10 code for this condition. Can you help? Idaho Subscriber Answer: The code you’ll want for this condition is M54.18 (Radiculopathy, sacral and sacrococcygeal region). Alternate phrasing alert: What you saw in the notes might have thrown you off the path to the proper diagnosis code. Thoracic neuritis (or radiculitis) NOS is listed as a synonym under M54.1 (Radiculopathy), the parent code of M54.18. Other synonyms that will track to M54.1-, per ICD-10, are: