Alphabetic Index FY2027

J91.0

Malignant pleural effusion

FY2027Chapter 10: Diseases of the respiratory system/J90–J94 Other diseases of the pleura

BillableComplete code, valid to report
Care settingsHospice: not accepted as primaryHospital CC

J91.0 (also written J910) is a billable ICD-10-CM diagnosis code for malignant pleural effusion. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 2 codes in category J91 (Pleural effusion in conditions classified elsewhere). The Alphabetic Index lists it under 2 entries. Its coding notes include a Code first instruction, a Use additional code instruction and 11 Excludes2 entries.

Code first

If the underlying condition listed here is present and known, sequence it first.

This code
  • underlying neoplasm (C00-D49)

Use additional code

Add the listed code as a secondary code, if known.

Also from chapter/block level (7 notes)
Inherited from Chapter 10 Diseases of the respiratory system
  • code, where applicable, to identify:
    • exposure to environmental tobacco smoke (Z77.22)
    • exposure to tobacco smoke in the perinatal period (P96.81)
    • history of tobacco dependence (Z87.891)
    • occupational exposure to environmental tobacco smoke (Z57.31)
    • tobacco dependence (F17.-)
    • tobacco use (Z72.0)

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

Inherited from J91 Pleural effusion in conditions classified elsewhere
  • pleural effusion in heart failure (I50.-)
  • pleural effusion in systemic lupus erythematosus (M32.13)
Also from chapter/block level (9 notes)
Inherited from Chapter 10 Diseases of the respiratory system
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • smoke inhalation (T59.81-)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Care settings

How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.

Hospice: not accepted as primary

Not accepted as the principal diagnosis on a hospice claim (bill types 081x and 082x). The Integrated OCE returns an edit for this code.
Reason: Manifestation code. Report the underlying condition first (see the Code first note).

Source: CMS Integrated Outpatient Code Editor (IOCE) v27.3, effective October 1, 2026, edit 86

Hospital CC

Counts as a complication or comorbidity (CC) when reported as a secondary diagnosis on an inpatient claim. It does not count when the principal diagnosis is one of the 27 codes in its exclusion list. Some MS-DRGs also ignore a CC or MCC that defines the DRG.

Source: CMS MS-DRG Definitions Manual v44, effective October 1, 2026, Appendix C

Notes

Also from chapter/block level (1 note)
Inherited from Chapter 10 Diseases of the respiratory system
  • When a respiratory condition is described as occurring in more than one site and is not specifically indexed, it should be classified to the lower anatomic site (e.g. tracheobronchitis to bronchitis in J40).

Alphabetic Index terms

Terms the official Alphabetic Index lists for this code. 2 entries