ICD-9-CM Diagnosis Code 401.0
Diagnosis Code: 401.0 (Raw: 4010)
Description: Malignant hypertension
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 401.0 is designated for Malignant hypertension. While superseded by ICD-10 for current healthcare encounters, it remains a recognized reference code for CMS Section 111 reporting, legacy claims adjudication, and historical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.