2026 ICD-10-CM Diagnosis Code I27.848Other Fontan-associated condition

ICD-10-CM Codes›I00–I99›I26-I28›I27

ICD-10-CM I27.848
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I27.848 is a billable ICD-10-CM diagnosis code for other Fontan-associated condition. 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.

I27.848 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 191 for payment year 2026.

Code Identity

ICD-10-CM Code
I27.848
Billable Status
Yes — Valid for Submission
Code Describes
Other Fontan-associated condition
Short Description
Other Fontan-associated condition
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 CodeI27.848Other Fontan-associated condition

Medicare Risk Adjustment (HCC)Billing

I27.848 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model, but it maps to payment categories in the other CMS models shown below.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
no payment category in the model that pays 100% of MA risk scores
Prior Model (CMS-HCC V24)
Not mapped under V24
this diagnosis newly risk-adjusts under the V28 model
Part D (RxHCC)
RxHCC 191 — Ventricular Septal Defect and Major Congenital Heart Disorders
also risk-adjusts in the Part D prescription drug model (V08)

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.

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Use Additional Code

  • code to specify the Fontan associated condition

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Code History & ChangesHistory

New Code I27.848 was added to the ICD-10-CM code set for FY 2026, effective October 1, 2025.

Replacement I27.848 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 I27.848Overview

What is the ICD-10 code for other Fontan-associated condition?

The ICD-10-CM code for other Fontan-associated condition is I27.848 (sometimes written as I27848). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is I27.848 (Fontan related circulation) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other Fontan-associated condition on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does I27.848 group to?

When other Fontan-associated condition 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.

Does I27.848 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage: I27.848 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 191 (Ventricular Septal Defect and Major Congenital Heart Disorders).