ICD-9-CM Diagnosis Code 511.81
Diagnosis Code: 511.81 (Raw: 51181)
Description: Malignant pleural effusion
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 511.81 is designated for Malignant pleural effusion. While superseded by ICD-10 for current healthcare encounters, it remains a recognized reference code for CMS Section 111 reporting, legacy claims adjudication, and historical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.