I27.84 ICD-10-CM Code: Fontan related circulation

Coder workflow for I27.84

MedCoder structured workflow — derived from this code’s own official record

Before you code I27.84

1. I27.84 is not reportable as written. Select the more specific code beneath it that the documentation supports. Codes are reported to the highest level of specificity the classification provides (Guidelines I.B.2).

   ReviewI27.840, I27.841, I27.848, I27.849

   See the relationships section · Guide: How to choose an ICD-10-CM code →

Choose the right path

1. Does the documentation support one of the more specific codes beneath I27.84?
   Yes → Select that code and continue the checks below on its own page.
   No → I27.84 cannot be reported as written; query for the specificity its subcategory needs.

   ReviewI27.840, I27.841, I27.848, I27.849

Consider I27.84. Then confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement

Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).

Acuity

Acute or chronic as documented; when both are documented and separate codes exist, both are reported with the acute code first (Guidelines I.B.8).

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Verify Before Coding

• Not billable as written — a more specific code is required: I27.840, I27.841, I27.848, I27.849.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name I27.84 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes2 note: Z98 — Other postprocedural states.

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

Contextual Map

Every relationship of I27.84 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run I27.84 with this related code in Claim Check

Hierarchy

• I00-I99 — Chapter 9: Diseases of the Circulatory System (I00-I99) (I00-I99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I26-I28 — Pulmonary heart disease and diseases of pulmonary circulation[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Excludes2 notes

• Z98 — Other postprocedural states[Excludes2]: “Fontan related circulation (I27.84-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Nearest codes (20)

• I27 — Other pulmonary heart diseases[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I27.0 — Primary pulmonary hypertension[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I27.1 — Kyphoscoliotic heart disease[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I27.2 — Other secondary pulmonary hypertension[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I27.20 — Pulmonary hypertension, unspecified[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I27.21 — Secondary pulmonary arterial hypertension[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I27.22 — Pulmonary hypertension due to left heart disease[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I27.23 — Pulmonary hypertension due to lung diseases and hypoxia[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 12 more

Change history

• FY2026 — Added to the code set[Change history]— CMS release files (code change ledger) · icd10cm-fy2026

Common coding questions

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data

CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page

Claim edits Official source data

CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page

Change history and date-of-service validity Official source data

CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page

Comparisons, relationships and the contextual map MedCoder structured relationship

Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears

Summary and FAQ answers MedCoder explanation

Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Nearest Codes in This Family

Official ICD-10-CM classifications closest to I27.84 in its code family, with their registry titles.

• I27.29 — Other secondary pulmonary hypertension
• I27.8 — Other specified pulmonary heart diseases
• I27.81 — Cor pulmonale (chronic)
• I27.82 — Chronic pulmonary embolism
• I27.83 — Eisenmenger's syndrome
• I27.840 — Fontan-associated liver disease [FALD]
• I27.841 — Fontan-associated lymphatic dysfunction
• I27.848 — Other Fontan-associated condition
• I27.849 — Fontan related circulation, unspecified
• I27.89 — Other specified pulmonary heart diseases

View all codes in the I27 family