ICD-10 Code J91.8 – Pleural effusion in other conditions classified elsewhere (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code J91.8 – Pleural effusion in other conditions classified elsewhere
What it is
This code identifies pleural fluid buildup caused by another documented condition, not the effusion itself as a primary diagnosis. Use it when the underlying disease is known and the effusion is secondary to that condition.
Clinical signs
Clinical features vary; refer to documentation. Common findings include shortness of breath, pleuritic chest discomfort, decreased breath sounds, and imaging evidence of fluid in the pleural space.
When to use this code
Use J91.8 when the record clearly states a pleural effusion due to another condition classified elsewhere, such as a systemic or thoracic disease. You should link the effusion to the documented underlying condition in the chart. If the cause is not specified, check documentation before coding.
Do not use for
Do not use this code for pleural effusion without a documented underlying cause, or when another more specific effusion code applies. Check documentation if the effusion is traumatic, infectious, or otherwise separately classified.
Coding tip
Always code the underlying condition first when it is documented, and use J91.8 only for the secondary pleural effusion.