2026 ICD-10-CM Diagnosis Code J91.8Pleural effusion in other conditions classified elsewhere

ICD-10-CM Codes›J00–J99›J90-J94›J91

ICD-10-CM J91.8
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

J91.8 is a billable ICD-10-CM diagnosis code for pleural effusion in other conditions classified elsewhere. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 186 through 188. The code is a manifestation code that cannot be reported as the principal diagnosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Pleurisy, pleural effusion and pulmonary collapse.

Code Identity

ICD-10-CM Code
J91.8
Billable Status
Yes — Valid for Submission
Code Describes
Pleural effusion in other conditions classified elsewhere
Short Description
Pleural effusion in other conditions classified elsewhere
Same as the full description in the CMS dataset.
Parent Code
J91
Pleural effusion in conditions classified elsewhere

Code Classification

ChapterJ00–J99Diseases of the respiratory system
SectionJ90-J94Other diseases of the pleura
CategoryJ91Pleural effusion in conditions classified elsewhere
This CodeJ91.8Pleural effusion in other conditions classified elsewhere

Code EditsBilling

Medicare Code Editor checks that affect claim validity for J91.8.

Manifestation diagnoses
Manifestation codes describe the manifestation of an underlying disease, not the disease itself, and therefore should not be used as a principal diagnosis.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Benign asbestos pleural effusion
  • Drug-induced pleural effusion
  • Meigs' syndrome
  • Pleural effusion associated with hepatic disorder
  • Pleural effusion associated with pulmonary infection
  • Pleural effusion caused by bacteria
  • Pleural effusion due to another disorder
  • Pleural effusion due to congestive heart failure
  • Pleural effusion due to disorder of pancreas
  • Pleural effusion due to malignant neoplastic disease
  • Pleural effusion due to neoplastic disease
  • Pleural effusion due to pancreatitis

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Code First

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Effusion
      • pleura, pleurisy, pleuritic, pleuropericardial
        • in conditions classified elsewhere

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR RSP011
Pleurisy, pleural effusion and pulmonary collapse
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Pleural Disorders

Your pleura is a large, thin sheet of tissue that wraps around the outside of your lungs and lines the inside of your chest cavity. Between the layers of the pleura is a very thin space. Normally it's filled with a small amount of fluid.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert J91.8 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
511.9 Pleural effusion NOS
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About J91.8Overview

Is J91.8 (Pleural effusion in conditions classified elsewhere) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report pleural effusion in other conditions classified elsewhere on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does J91.8 group to?

On inpatient claims, pleural effusion in other conditions classified elsewhere maps to MS-DRG 186, 187, 188, with relative weights from 0.7172 to 1.5585 depending on complications. Higher weights mean higher Medicare reimbursement.

Can J91.8 be a principal diagnosis?

No. This is a manifestation code: pleural effusion in other conditions classified elsewhere describes the manifestation of an underlying disease rather than the disease itself, so the underlying condition is sequenced first.

What is the ICD-9 equivalent of J91.8?

Under the General Equivalence Mappings, pleural effusion in other conditions classified elsewhere converts to ICD-9-CM 511.9 (pleural effusion NOS). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.