2026 ICD-10-CM Diagnosis Code I27.849

Fontan related circulation, unspecified

ICD-10-CM Code:
I27.849
ICD-10 Code for:
Fontan related circulation, unspecified
Is Billable?
Yes - Valid for Submission
Code Navigator:

I27.849 is a billable diagnosis code used to specify a medical diagnosis of fontan related circulation, unspecified. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2025 through September 30, 2026.

Unspecified diagnosis codes like I27.849 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

Code Classification

  • Diseases of the circulatory system
    I00–I99
    • Pulmonary heart disease and diseases of pulmonary circulation
      I26-I28
      • Other pulmonary heart diseases
        I27

New 2026 ICD-10-CM Code

I27.849 is new to ICD-10-CM code set for the FY 2026, effective October 1, 2025. The National Center for Health Statistics (NCHS) has published an update to the ICD-10-CM diagnosis codes which became effective October 1, 2025. This is a new and revised code for the FY 2026 (October 1, 2025 - September 30, 2026).

Index to Diseases and Injuries References

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

Index of External Cause of Injuries

References found for this diagnosis code in the External Cause of Injuries Index:

    • Circulation
      • Fontan related

Replacement Code

I27849 replaces the following previously assigned ICD-10-CM code(s):

  • I27.89 - Other specified pulmonary heart diseases

Code History

  • FY 2026 - Code Added, effective from 10/1/2025 through 9/30/2026