ICD-9-CM Diagnosis Code 523.40
Diagnosis Code: 523.40 (Raw: 52340)
Description: Chronic periodontitis, unspecified
Classification: International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM)
Fiscal Year: 2026 Reference
CMS Section 111 Status: Valid for reporting.
Overview & Historical Usage
ICD-9-CM code 523.40 is designated for Chronic periodontitis, unspecified. While superseded by ICD-10 for current healthcare encounters, it remains a recognized reference code for CMS Section 111 reporting, legacy claims adjudication, and historical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.