2026 ICD-10-CM Diagnosis Code J85.1Abscess of lung with pneumonia
ICD-10-CM Codes›J00–J99›J85-J86›J85
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- Risk Adjusts — HCC 283
- Not Chronic
J85.1 is a billable ICD-10-CM diagnosis code for abscess of lung with pneumonia. 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 22 closely related codes. Coders also document this condition as abscess of lung. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Pneumonia (except that caused by tuberculosis).
For Medicare Advantage risk adjustment, J85.1 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
Code Classification
Medicare Risk Adjustment (HCC)Billing
J85.1 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.
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 lung
- Abscess of lung with pneumonia
- Confluent bronchopneumonia with abscess formation
- Confluent pneumonia
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Code Also
- the type of pneumonia
A "code also" note instructs that two codes may be required to fully describe a condition, but this note does not provide sequencing direction.
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.
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 J85.1 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About J85.1Overview
What is the ICD-10 code for abscess of lung with pneumonia?
The ICD-10-CM code for abscess of lung with pneumonia is J85.1 (sometimes written as J851). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is J85.1 (Abscess of lung and mediastinum) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report abscess of lung with pneumonia on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does J85.1 group to?
When abscess of lung with pneumonia 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 J85.1 a CC or MCC?
CMS lists J85.1 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 22 closely related codes in its exclusion list.
What is the ICD-9 equivalent of J85.1?
Under the General Equivalence Mappings, abscess of lung with pneumonia converts to ICD-9-CM 513.0 (abscess of lung). The mapping is approximate, so confirm the match fits the documentation.
What HCC is J85.1?
J85.1 (abscess of lung with pneumonia) 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 J85.1 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, J85.1 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.
