2026 ICD-10-CM Diagnosis Code I27.849Fontan related circulation, unspecified

ICD-10-CM Codes›I00–I99›I26-I28›I27

ICD-10-CM I27.849
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I27.849 is a billable ICD-10-CM diagnosis code for fontan related circulation, unspecified. 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.

Code Identity

ICD-10-CM Code
I27.849
Billable Status
Yes — Valid for Submission
Code Describes
Fontan related circulation, unspecified
Short Description
Fontan related circulation, unspecified
Same as the full description in the CMS dataset.
Parent Code
I27.84
Fontan related circulation

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI26-I28Pulmonary heart disease and diseases of pulmonary circulation
CategoryI27Other pulmonary heart diseases
This CodeI27.849Fontan related circulation, unspecified

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Circulation
      • Fontan related

Code History & ChangesHistory

New Code I27.849 was added to the ICD-10-CM code set for FY 2026, effective October 1, 2025.

Replacement I27.849 replaces the following previously assigned code(s):

  • I27.89 - Other specified pulmonary heart diseases
FY 2026AddedAdded to the ICD-10-CM code setEffective October 1, 2025.
FY 2026CurrentRevised in the current code setEffective October 1, 2025 through September 30, 2026.

Questions About I27.849Overview

Is I27.849 (Fontan related circulation) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report fontan related circulation, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does I27.849 group to?

When fontan related circulation, unspecified 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.