ICD-9-CM Diagnosis Code 355.9
Diagnosis Code: 355.9 (Raw: 3559)
Description: Mononeuritis of unspecified site
Classification: International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM)
Fiscal Year: 2026 Reference
CMS Section 111 Status: Valid for reporting (Excluded from No-Fault liability reporting).
Overview & Historical Usage
ICD-9-CM code 355.9 is designated for Mononeuritis of unspecified site. While superseded by ICD-10 for current healthcare encounters, it remains a recognized reference code for CMS Section 111 reporting, legacy claims adjudication, and historical clinical data analysis.