J91.8 Pleural effusion in other conditions classified elsewhere
Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.
Code first
underlying disease, such as:
filariasis (B74.0-B74.9)
influenza (J09.X2, J10.1, J11.1)
Applies from J91 Pleural effusion in conditions classified elsewhere
Excludes2 (not included here)
pleural effusion in heart failure (I50.-)
pleural effusion in systemic lupus erythematosus (M32.13)
MS-DRG index
Defines the logic of DRG(s) 186-188 in MDC 04.
Approximate ICD-9-CM (GEMs)
511.9 Unspecified pleural effusion (approximate)
Medicare Code Edits (MCE v43.1 (April 2026))
Manifestation codes as principal diagnosis: Manifestation codes describe the manifestation of an underlying disease, not the disease itself, and are not allowed as principal diagnosis.
Code annotations containing back-references to J91.8
Back-references to J91.8
Use Additional: J09.X2 Influenza due to identified novel influenza A virus with other respiratory manifestations ("pleural effusion (J91.8)")
Use Additional: J10.1 Influenza due to other identified influenza virus with other respiratory manifestations ("code for associated pleural effusion, if applicable (J91.8)")
Use Additional: J11.1 Influenza due to unidentified influenza virus with other respiratory manifestations ("code for associated pleural effusion, if applicable (J91.8)")