2026 ICD-10-CM Diagnosis Code I27.83Eisenmenger's syndrome
ICD-10-CM Codes›I00–I99›I26-I28›I27
- Billable — Valid for Submission
- Risk Adjusts — HCC 226
- Chronic Condition
I27.83 is a billable ICD-10-CM diagnosis code for Eisenmenger's syndrome. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 314 through 316. Coders also document this condition as Eisenmenger's complex. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Pulmonary heart disease.
For Medicare Advantage risk adjustment, I27.83 maps to CMS-HCC Category 226 (Heart Failure, Except End Stage and Acute) under the V28 model, adding a risk factor of about 0.360 for a community, non-dual, aged beneficiary in payment year 2026.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
I27.83 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.
- Eisenmenger's complex
- Eisenmenger's syndrome
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Eisenmenger's complex
- (Irreversible) Eisenmenger's disease
- Pulmonary hypertension with right to left shunt related to congenital heart disease
Code Also
- underlying heart defect, if known, such as:
- atrial septal defect Q21.1
- Eisenmenger's defect Q21.8
- patent ductus arteriosus Q25.0
- ventricular septal defect Q21.0
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
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.
Disease, diseased See Also: Syndrome;
Eisenmenger's (irreversible) I27.83
complex or syndrome I27.83
Hypertension, hypertensive (accelerated) (benign) (essential) (idiopathic) (malignant) (systemic) I10
Syndrome See Also: Disease;
Eisenmenger's I27.83
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Pulmonary Hypertension
Pulmonary hypertension, sometimes called PH, is a serious condition that affects the blood vessels in the lungs. It develops when the blood pressure in your lungs is higher than normal.
The full article covers:
- What is pulmonary hypertension?
- What causes pulmonary hypertension?
- Who is more likely to develop pulmonary hypertension?
- What are the symptoms of pulmonary hypertension?
- What other problems can pulmonary hypertension cause?
- How is pulmonary hypertension diagnosed?
- What are the treatments for pulmonary hypertension?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert I27.83 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code History & ChangesHistory
Replacement I27.83 replaces the following previously assigned code(s):
- I27.89 - Other specified pulmonary heart diseases
Questions About I27.83Overview
What is the ICD-10 code for Eisenmenger's syndrome?
The ICD-10-CM code for Eisenmenger's syndrome is I27.83 (sometimes written as I2783). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is I27.83 (Other specified pulmonary heart diseases) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report Eisenmenger's syndrome on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does I27.83 group to?
When Eisenmenger's syndrome is the principal diagnosis on an inpatient stay, it groups to MS-DRG 314, 315, 316, with relative weights from 0.6821 to 2.0852 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of I27.83?
Under the General Equivalence Mappings, Eisenmenger's syndrome converts to ICD-9-CM 745.4 (ventricular sept defect). The mapping is approximate, so confirm the match fits the documentation.
What HCC is I27.83?
I27.83 (Eisenmenger's syndrome) maps to CMS-HCC Category 226 (Heart Failure, Except End Stage and Acute), commonly written as HCC 226, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2026. 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 183.
Does I27.83 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, I27.83 adds a risk adjustment factor of about 0.360 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.217 to 0.537 depending on the payment segment). A more severe related category (HCC 221, HCC 222, HCC 223, HCC 224, and HCC 225) supersedes it when both are reported. See the full factor table on the HCC 226 category page.
