2027 ICD-10-CM Diagnosis Code I26.01Septic pulmonary embolism with acute cor pulmonale

ICD-10-CM Codes›I00–I99›I26-I28›I26

ICD-10-CM I26.01
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

I26.01 is a billable ICD-10-CM diagnosis code for septic pulmonary embolism with acute cor pulmonale. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 173, 175 through 176, 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 30 closely related codes. The code is not accepted as a principal diagnosis by the Medicare Code Editor. Coders also document this condition as acute cor pulmonale. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Acute pulmonary embolism and Bacterial infections.

For Medicare Advantage risk adjustment, I26.01 maps to CMS-HCC Category 267 (Deep Vein Thrombosis and Pulmonary Embolism) under the V28 model, adding a risk factor of about 0.294 for a community, non-dual, aged beneficiary in payment year 2027.

Code Identity

ICD-10-CM Code
I26.01
Billable Status
Yes — Valid for Submission
Code Describes
Septic pulmonary embolism with acute cor pulmonale
Short Description
Septic pulmonary embolism with acute cor pulmonale
Same as the full description in the CMS dataset.
Parent Code
I26.0
Pulmonary embolism with acute cor pulmonale

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI26-I28Pulmonary heart disease and diseases of pulmonary circulation
CategoryI26Pulmonary embolism
This CodeI26.01Septic pulmonary embolism with acute cor pulmonale

Code EditsBilling

Medicare Code Editor checks that affect claim validity for I26.01.

Unacceptable principal diagnosis
There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

Medicare Risk Adjustment (HCC)Billing

I26.01 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 2027.

CMS-HCC V28 Category (Payment Model)
HCC 267— Deep Vein Thrombosis and Pulmonary Embolism
Payment HCC · PY 2027 one of 167 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.294
community, non-dual, aged · ranges 0.245–0.568 across segments
Hierarchy
Top of its hierarchy
HCC 267 is not superseded by any other condition category
Prior Model (CMS-HCC V24)
HCC 85
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 85 · PACE (CMS-HCC V22): HCC 107 · ESRD (V21): HCC 85 · ESRD (V21): HCC 107 · ESRD (V24): HCC 85 · ESRD (V24): HCC 107
ESRD V21 weights: 0.082 dialysis, 0.186–0.336 functioning graft · ESRD V21 weights: 0.126 dialysis, 0.300–0.431 functioning graft · ESRD V24 weights: 0.063 dialysis, 0.169–0.302 functioning graft · ESRD V24 weights: 0.144 dialysis, 0.324–0.586 functioning graft
Part D (RxHCC)
RxHCC 215 — Venous Thromboembolism
also risk-adjusts in the Part D prescription drug model (V08)

Source: CMS Payment Year 2027 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.

  • Acute cor pulmonale
  • Acute cor pulmonale due to septic pulmonary embolism
  • Acute pulmonary embolism
  • Cor pulmonale
  • Right ventricular failure due to pulmonary vascular disease
  • Septic embolus of artery
  • Septic pulmonary embolism

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to I26.01: its own notes plus those printed at I26 and Chapter 9. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From I26 Pulmonary embolism applies to 12 codes
  • pulmonary (acute) (artery)(vein) infarction
  • pulmonary (acute) (artery)(vein) thromboembolism
  • pulmonary (acute) (artery)(vein) thrombosis

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From I26 Pulmonary embolism applies to 12 codes
  • cor pulmonale without embolism (I27.81)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From I26 Pulmonary embolism applies to 12 codes
  • chronic pulmonary embolism (I27.82)
  • personal history of pulmonary embolism (Z86.711)
  • pulmonary embolism complicating abortion, ectopic or molar pregnancy (O00-O07, O08.2)
  • pulmonary embolism complicating pregnancy, childbirth and the puerperium (O88.-)
  • pulmonary embolism due to trauma (T79.0, T79.1)
  • pulmonary embolism due to complications of surgical and medical care (T80.0, T81.7-, T82.8-)
  • septic (non-pulmonary) arterial embolism (I76)
From Chapter 9 (I00-I99) Diseases of the circulatory system applies to 1,433 codes
  • 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)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
  • systemic connective tissue disorders (M30-M36)
  • transient cerebral ischemic attacks and related syndromes (G45.-)

Code First

The underlying condition named in the note is sequenced before this code.

  • underlying infection

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name I26.01, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming I26.01: they are not reported together with it, unless the two conditions are unrelated.

  • I27.81 Cor pulmonale (chronic)
    acute cor pulmonale (I26.0-) names I26.0-, which includes this code

Excludes2 3

These codes carry an Excludes2 note naming I26.01: its condition is not part of those codes, and both may be reported when the patient has both.

  • I76 Septic arterial embolism
    septic pulmonary embolism (I26.01, I26.90)
  • I74 Arterial embolism and thrombosis
    pulmonary embolism and thrombosis (I26.-) names I26.-, which includes this code
  • I82 Other venous embolism and thrombosis
    pulmonary (I26.-) names I26.-, which includes this code

Code First 2

These codes say to code first a condition named in the note, and I26.01 is one of the conditions named.

  • I5A Non-ischemic myocardial injury (non-traumatic)
    pulmonary embolism (I26.-) names I26.-, which includes this code
  • U09.9 Post COVID-19 condition, unspecified
    pulmonary embolism (I26.-) names I26.-, which includes this code

Code Also 1

These codes say I26.01 may also be needed to fully describe the condition. The note gives no sequencing direction.

  • I27.24 Chronic thromboembolic pulmonary hypertension
    associated pulmonary embolism, if applicable (I26.-, I27.82) names I26.-, which includes this code

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 CIR013
Acute pulmonary embolism
Default principal diagnosis: inpatient No · outpatient Yes
CCSR INF003
Bacterial infections
Default principal diagnosis: inpatient No · outpatient No

Clinical InformationClinical

  • Pulmonary Embolism

    blocking of the pulmonary artery or one of its branches by an embolus.

Patient EducationClinical

Pulmonary Embolism

A pulmonary embolism (PE) is a sudden blockage in a lung artery. It usually happens when a blood clot breaks loose and travels through the bloodstream to the lungs. PE is a serious condition that can cause:

The full article covers:

  • What is a pulmonary embolism (PE)?
  • What causes a pulmonary embolism (PE)?
  • Who is more likely to develop a pulmonary embolism (PE)?
  • What are the symptoms of a pulmonary embolism (PE)?
  • How is a pulmonary embolism (PE) diagnosed?
  • What are the treatments for a pulmonary embolism (PE)?
  • Can pulmonary embolism (PE) be prevented?

Read the full article at MedlinePlus

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

Convert I26.01 to ICD-9-CMHistory

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

ICD-9-CM
415.12 Septic pulmonary embolsm
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
415.0 Acute cor pulmonale
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About I26.01Overview

What is the ICD-10 code for septic pulmonary embolism with acute cor pulmonale?

The ICD-10-CM code for septic pulmonary embolism with acute cor pulmonale is I26.01 (sometimes written as I2601). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is I26.01 (Pulmonary embolism with acute cor pulmonale) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report septic pulmonary embolism with acute cor pulmonale on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does I26.01 group to?

On inpatient claims, septic pulmonary embolism with acute cor pulmonale maps to MS-DRG 793, 791, 175, 176, 173, with relative weights from 0.8061 to 4.2192 depending on complications. Higher weights mean higher Medicare reimbursement.

Is I26.01 a CC or MCC?

CMS lists I26.01 as an MCC (major complication or comorbidity) for FY 2027. 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 30 closely related codes in its exclusion list.

Can I26.01 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because septic pulmonary embolism with acute cor pulmonale describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

What HCC is I26.01?

I26.01 (septic pulmonary embolism with acute cor pulmonale) maps to CMS-HCC Category 267 (Deep Vein Thrombosis and Pulmonary Embolism), commonly written as HCC 267, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 85 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 215.

Does I26.01 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, I26.01 adds a risk adjustment factor of about 0.294 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.245 to 0.568 depending on the payment segment). HCC 267 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 267 category page.