2026 ICD-10-CM Diagnosis Code J86.9Pyothorax without fistula

ICD-10-CM Codes›J00–J99›J85-J86›J86

ICD-10-CM J86.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

J86.9 is a billable ICD-10-CM diagnosis code for pyothorax without fistula. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 177 through 179, 791, 793. As a secondary diagnosis, it counts as a major complication or comorbidity (MCC) and places an inpatient stay in the highest severity level of its MS-DRG family. It does not count, however, when the principal diagnosis is one of 12 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Pleurisy, pleural effusion and pulmonary collapse.

For Medicare Advantage risk adjustment, J86.9 maps to CMS-HCC Category 283 (Empyema, Lung Abscess) under the V28 model, adding a risk factor of about 0.204 for a community, non-dual, aged beneficiary in payment year 2026.

Code Identity

ICD-10-CM Code
J86.9
Billable Status
Yes — Valid for Submission
Code Describes
Pyothorax without fistula
Short Description
Pyothorax without fistula
Same as the full description in the CMS dataset.
Parent Code
J86
Pyothorax

Code Classification

ChapterJ00–J99Diseases of the respiratory system
SectionJ85-J86Suppurative and necrotic conditions of the lower respiratory tract
CategoryJ86Pyothorax
This CodeJ86.9Pyothorax without fistula

Medicare Risk Adjustment (HCC)Billing

J86.9 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2026.

CMS-HCC V28 Category (Payment Model)
HCC 283— Empyema, Lung Abscess
Payment HCC · PY 2026 one of 7 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.204
community, non-dual, aged · ranges 0.000–0.204 across segments
Hierarchy
Superseded by HCC 282
a more severe related category takes the payment when both are reported
Prior Model (CMS-HCC V24)
HCC 115
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 115 · ESRD (V21): HCC 115 · ESRD (V24): HCC 115
ESRD V21 weights: 0.013 dialysis, 0.143–0.155 functioning graft · ESRD V24 weights: 0.030 dialysis, 0.154–0.248 functioning graft
Part D (RxHCC)
Not mapped
J86.9 does not risk-adjust in the RxHCC prescription drug model

Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abscess of pleural cavity
  • Abscess of thorax
  • Bacterial pleurisy
  • Bacterial pleurisy with effusion
  • Empyema
  • Empyema of pleura
  • Fibrinopurulent pleurisy
  • Fibrinous pleurisy
  • Loculated empyema
  • Pleurisy with effusion
  • Pneumococcal pleurisy
  • Pneumococcal pleurisy with effusion
  • Pyopneumothorax
  • Pyopneumothorax following infection by Coccidioides
  • Septic pleurisy
  • Seropurulent pleurisy
  • Staphylococcal pleurisy
  • Staphylococcal pleurisy with effusion
  • Streptococcal pleurisy
  • Streptococcal pleurisy with effusion

Tabular List NotesGuidance

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

Inclusion Terms

  • Abscess of pleura
  • Abscess of thorax
  • Empyema (chest) (lung) (pleura)
  • Fibrinopurulent pleurisy
  • Purulent pleurisy
  • Pyopneumothorax
  • Septic pleurisy
  • Seropurulent pleurisy
  • Suppurative pleurisy

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

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

CCSR RSP011
Pleurisy, pleural effusion and pulmonary collapse
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Cholecystitis

    inflammation of the gallbladder; generally caused by impairment of bile flow, gallstones in the biliary tract, infections, or other diseases.

  • Empyema

    presence of pus in a hollow organ or body cavity.

  • Empyema, Pleural

    suppurative inflammation of the pleural space.

  • Empyema, Subdural

    an intracranial or rarely intraspinal suppurative process invading the space between the inner surface of the dura mater and the outer surface of the arachnoid.

  • Empyema, Tuberculous

    empyema due to mycobacterium tuberculosis.

  • Mycobacterium tuberculosis

    a species of gram-positive, aerobic bacteria that produces tuberculosis in humans, other primates, cattle; dogs; and some other animals which have contact with humans. growth tends to be in serpentine, cordlike masses in which the bacilli show a parallel orientation.

Patient EducationClinical

Abscess

An abscess is a pocket of pus. You can get an abscess almost anywhere in your body. When an area of your body becomes infected, your body's immune system tries to fight the infection. White blood cells go to the infected area, collect within the damaged tissue, and cause inflammation. During this process, pus forms.

Read the full article at MedlinePlus

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

Convert J86.9 to ICD-9-CMHistory

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

ICD-9-CM
510.9 Empyema w/o fistula
Approximate The match is approximate rather than exact.
ICD-9-CM
511.0 Pleurisy w/o effus or TB
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 J86.9Overview

What is the ICD-10 code for pyothorax without fistula?

The ICD-10-CM code for pyothorax without fistula is J86.9 (sometimes written as J869). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is J86.9 (Pyothorax) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report pyothorax without fistula on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does J86.9 group to?

When pyothorax without fistula is the principal diagnosis on an inpatient stay, it groups to MS-DRG 177, 178, 179, 791, 793, with relative weights from 0.7550 to 4.1696 depending on complications. Higher weights mean higher Medicare reimbursement.

Is J86.9 a CC or MCC?

CMS lists J86.9 as an MCC (major complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it places the inpatient stay in the highest-weighted DRG of its severity family. It does not count when the principal diagnosis is one of the 12 closely related codes in its exclusion list.

What is the ICD-9 equivalent of J86.9?

Under the General Equivalence Mappings, pyothorax without fistula converts to ICD-9-CM 510.9 (empyema w/o fistula) and 511.0 (pleurisy w/o effus or TB). The mapping is approximate, so confirm the match fits the documentation.

What HCC is J86.9?

J86.9 (pyothorax without fistula) maps to CMS-HCC Category 283 (Empyema, Lung Abscess), commonly written as HCC 283, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2026. It mapped to HCC 115 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. It does not map to any RxHCC in the Part D prescription drug model.

Does J86.9 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, J86.9 adds a risk adjustment factor of about 0.204 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.000 to 0.204 depending on the payment segment). A more severe related category (HCC 282) supersedes it when both are reported. See the full factor table on the HCC 283 category page.