Pleural effusion in other conditions classified elsewhere

This code signifies the presence of fluid accumulation in the pleural space that is a manifestation of an underlying disease process, rather than a primary pleural disorder. It indicates a secondary pleural effusion where the etiology is specified and coded separately.

Apply this code when documentation clearly states pleural effusion secondary to another condition, such as congestive heart failure, malignancy, or renal failure. The underlying causative condition must also be coded. Documentation should explicitly link the effusion to the primary diagnosis.

• Always sequence the underlying condition first, as this code is an "in other conditions classified elsewhere" code.
• Do not use this code for pleural effusions where the cause is unknown or not specified; instead, consider codes like R91.8 (Other nonspecific abnormal findings on diagnostic imaging of lung) or J90 (Pleural effusion, not elsewhere classified).
• Ensure the medical record clearly identifies the primary diagnosis responsible for the pleural effusion to support accurate sequencing.