2026 ICD-10-CM Diagnosis Code J91.0Malignant pleural effusion
ICD-10-CM Codes›J00–J99›J90-J94›J91
- Billable — Valid for Submission
- Chronic Condition
J91.0 is a billable ICD-10-CM diagnosis code for malignant pleural effusion. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 180 through 182. 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 Conditions due to neoplasm or the treatment of neoplasm; and Pleurisy, pleural effusion and pulmonary collapse.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for J91.0.
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Code First
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- Effusion
- malignant pleural - J91.0
- pleura, pleurisy, pleuritic, pleuropericardial - J90
- malignant - J91.0
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Effusion
- malignant pleural
- Effusion
- pleura, pleurisy, pleuritic, pleuropericardial
- malignant
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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
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Convert J91.0 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About J91.0Overview
Is J91.0 (Pleural effusion in conditions classified elsewhere) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report malignant pleural effusion on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does J91.0 group to?
On inpatient claims, malignant pleural effusion maps to MS-DRG 180, 181, 182, with relative weights from 0.7440 to 1.7660 depending on complications. Higher weights mean higher Medicare reimbursement.
Can J91.0 be a principal diagnosis?
No. This is a manifestation code: malignant pleural effusion 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 J91.0?
Under the General Equivalence Mappings, malignant pleural effusion converts to ICD-9-CM 511.81 (malignant pleural effusn). The mapping is a direct match.
Footnotes
[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:
- The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
- The condition places limitations on self-care, independent living, and social interactions.
