ICD-9-CM Diagnosis Code 491.9
Diagnosis Code: 491.9 (Raw: 4919)
Description: Unspecified chronic bronchitis
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 491.9 is designated for Unspecified chronic bronchitis. While superseded by ICD-10 for current healthcare encounters, it remains a recognized reference code for CMS Section 111 reporting, legacy claims adjudication, and historical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.