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ICD-10-CM 2027 diagnosis code

I27.841Fontan-associated lymphatic dysfunction

✓ Billable / specific

I27.841 is a valid, billable ICD-10-CM code for fontan-associated lymphatic dysfunction. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Code last changed in FY2026 (effective October 1, 2025). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About I27.841

I27.841 is the ICD-10-CM diagnosis code for Fontan-associated lymphatic dysfunction. It belongs to category I27 (other pulmonary heart diseases), block I26-I28 (pulmonary heart disease and diseases of pulmonary circulation) and chapter 9 (diseases of the circulatory system). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within I27.84 (Fontan related circulation), I27.841 is specifically for Fontan-associated lymphatic dysfunction. Related codes cover Fontan-associated liver disease [FALD] (I27.840), other Fontan-associated condition (I27.848) and unspecified (I27.849).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 808 (Major Hematological and Immunological Diagnoses Except Sickle Cell Crisis and Coagulation Disorders with MCC, relative weight 2.1705), DRG 809 (Major Hematological and Immunological Diagnoses Except Sickle Cell Crisis and Coagulation Disorders with CC, relative weight 1.2262) and DRG 810 (Major Hematological and Immunological Diagnoses Except Sickle Cell Crisis and Coagulation Disorders without CC/MCC, relative weight 1.075), in MDC 16 (Diseases and Disorders of the Blood and Blood Forming Organs and Immunological Disorders), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It was added in FY2026, effective October 1, 2025.

Coding notes

Code alsoTwo codes may be needed; sequencing depends on circumstances
  • associated conditions such as:
  • chylothorax (J94.0)
  • Fontan associated protein-losing enteropathy (K90.49)
  • plastic (obstructive) bronchitis (J44.89)

Notes that apply from higher levels

Instructions written at a parent level also apply to I27.841.

Broader instructions also apply from Chapter 9: Diseases of the circulatory system.

Alphabetic index entries

2 entries

Terms in the official ICD-10-CM index that lead to I27.841.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2026 (effective 10/1/2025): Added
  • No changes since FY2026.

Common questions about I27.841

Is I27.841 billable?

Yes. I27.841 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can I27.841 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict I27.841 as a principal diagnosis.

Is I27.841 a CC or MCC?

No. I27.841 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does I27.841 group to?

I27.841 is used in the MS-DRG v44.0 logic for MS-DRG 808 (Major Hematological and Immunological Diagnoses Except Sickle Cell Crisis and Coagulation Disorders with MCC), MS-DRG 809 (Major Hematological and Immunological Diagnoses Except Sickle Cell Crisis and Coagulation Disorders with CC) and MS-DRG 810 (Major Hematological and Immunological Diagnoses Except Sickle Cell Crisis and Coagulation Disorders without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.