2026 ICD-10-CM Diagnosis Code J15.5Pneumonia due to Escherichia coli
ICD-10-CM Codes›J00–J99›J09-J18›J15
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- Risk Adjusts — HCC 282
- Not Chronic
J15.5 is a billable ICD-10-CM diagnosis code for pneumonia due to Escherichia coli. 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, 974 through 976. 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 129 closely related codes. Coders also document this condition as bronchopneumonia caused by Escherichia coli. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections and Pneumonia (except that caused by tuberculosis).
For Medicare Advantage risk adjustment, J15.5 maps to CMS-HCC Category 282 (Aspiration and Specified Bacterial Pneumonias) under the V28 model, adding a risk factor of about 0.440 for a community, non-dual, aged beneficiary in payment year 2026.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
J15.5 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.
- Bronchopneumonia caused by Escherichia coli
- Pneumonia caused by Escherichia coli
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
E. Coli Infections
E. coli is the name of a type of bacteria that lives in your intestines. Most types of E. coli are harmless. However, some types can make you sick and cause diarrhea. One type causes travelers' diarrhea. The worst type of E. coli causes bloody diarrhea, and can sometimes cause kidney failure and even death.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert J15.5 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About J15.5Overview
What is the ICD-10 code for pneumonia due to Escherichia coli?
The ICD-10-CM code for pneumonia due to Escherichia coli is J15.5 (sometimes written as J155). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is J15.5 (Bacterial pneumonia, not elsewhere classified) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report pneumonia due to Escherichia coli on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does J15.5 group to?
When pneumonia due to Escherichia coli is the principal diagnosis on an inpatient stay, it groups to MS-DRG 177, 178, 179, 791, 793, 974, 975, 976, with relative weights from 0.7550 to 4.1696 depending on complications. Higher weights mean higher Medicare reimbursement.
Is J15.5 a CC or MCC?
CMS lists J15.5 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 129 closely related codes in its exclusion list.
What is the ICD-9 equivalent of J15.5?
Under the General Equivalence Mappings, pneumonia due to Escherichia coli converts to ICD-9-CM 482.82 (pneumonia e coli). The mapping is a direct match.
What HCC is J15.5?
J15.5 (pneumonia due to Escherichia coli) maps to CMS-HCC Category 282 (Aspiration and Specified Bacterial Pneumonias), commonly written as HCC 282, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2026. It mapped to HCC 114 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 J15.5 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, J15.5 adds a risk adjustment factor of about 0.440 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.173 to 0.538 depending on the payment segment). HCC 282 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 282 category page.
