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

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
1 use-additional code
Risk adjustment
RxHCC V08 category 191

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v44, Appendix B.

  • MS-DRG 314 — OTHER CIRCULATORY SYSTEM DIAGNOSES WITH MCC (MDC 05)
  • MS-DRG 315 — OTHER CIRCULATORY SYSTEM DIAGNOSES WITH CC (MDC 05)
  • MS-DRG 316 — OTHER CIRCULATORY SYSTEM DIAGNOSES WITHOUT CC/MCC (MDC 05)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for I27.848 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2027Effective: October 1, 2026

Trace:FY2027 changesChange historyRelease, file and checksum

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • Use additional code to specify the Fontan associated condition

Coder workflow for I27.848

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

Before you code I27.848

  1. “Other” (NEC) means the condition is specified in the record but no dedicated code captures it. Confirm the documented form is not one a sibling code names before settling on I27.848; if the record states no specifics at all, the unspecified sibling applies instead. “Other” codes are for documented conditions the classification gives no specific code; “unspecified” codes are for records lacking the detail (Guidelines I.A.9.a, I.A.9.b).

    ReviewI27.840, I27.841

    See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →

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).
The conditions the Use Additional Code note names
Reported with this code when documented; a conditional instruction (“if applicable”, “if known”) applies only when the record supports it.
Any detail beyond this code’s title
What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.

Official instructions as workflow

  • Use Additional Code — after identifying I27.848(1 note)

    Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with I27.848 when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

    See the official tabular notes · Guidelines I.A.13

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: A condition the Use Additional Code note names is documented.

Coding question: Is a second code reported with I27.848?

Path: Review the Use Additional Code note and the code it names.

Reason: The additional code is reported when the record documents the condition; a conditional instruction applies only when its condition is met (Guidelines I.A.13).

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.

Don’t confuse I27.848 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of I27.848 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

  • I27.849— Specificity relationship (Review)

    Overlapping diagnoses in the same category.

    Overlapping codes in the same category — the documentation decides which is the more specific fit.

    What moves you there: A record that documents no more than “Fontan related circulation, unspecified” takes I27.849; specificity in the record moves it back here.

    Full comparison: I27.848 vs I27.849 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Code Overview

Other Fontan-associated condition is a billable ICD-10-CM diagnosis code (I27.848).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Indexed Clinical Terms (2)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Official Coding Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Verbatim excerpts from the ICD-10-CM Official Guidelines for Coding and Reporting (CMS/NCHS) that govern this code.

Chapter 9: Diseases of the Circulatory System (I00 -I99)

11) Pulmonary Hypertension Pulmonary hypertension is classified to category I27, Other pulmonary heart diseases. For secondary pulmonary hypertension (I27.1, I27.2-), code also any associated conditions or adverse effects of drugs or toxins. The sequencing is based on the reason for the encounter, except for adverse effects of drugs (See Section I.C.19.e.).

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

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 I27.848 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 (via I27.84.-).

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

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.

Named in the grouper logic of 3 MS-DRGs: DRG 314 (MDC 05), DRG 315 (MDC 05), DRG 316 (MDC 05).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):CIR038 — Postprocedural or postoperative circulatory system complication (default); CIR014 — Pulmonary heart disease.

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (Postprocedural or postoperative circulatory system complication, Pulmonary heart disease).

I27.21 — Secondary pulmonary arterial hypertension, I27.22 — Pulmonary hypertension due to left heart disease, I27.23 — Pulmonary hypertension due to lung diseases and hypoxia, I27.24 — Chronic thromboembolic pulmonary hypertension, I27.29 — Other secondary pulmonary hypertension, 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, I27.849 — Fontan related circulation, unspecified, I27.89 — Other specified pulmonary heart diseases, I27.9 — Pulmonary heart disease, unspecified, I28.0 — Arteriovenous fistula of pulmonary vessels, I28.1 — Aneurysm of pulmonary artery, I28.8 — Other diseases of pulmonary vessels, I28.9 — Disease of pulmonary vessels, unspecified, I97.0 — Postcardiotomy syndrome, I97.110 — Postprocedural cardiac insufficiency following cardiac surgery, I97.111 — Postprocedural cardiac insufficiency following other surgery, +43 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main terms “Circulation”, “Condition”; these codes share that main term but sit in a different category of the Tabular List.

I99.8 — Other disorder of circulatory system (collateral, any site), I99.9 — Unspecified disorder of circulatory system (defective), P29.38 — Other persistent fetal circulation (fetal, persistent), P29.89 — Other cardiovascular disorders originating in the perinatal period (failure, newborn), Q28.9 — Congenital malformation of circulatory system, unspecified (embryonic), R57.9 — Shock, unspecified (failure), U09.9 — Post COVID-19 condition, unspecified (post COVID-19)

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

Gamma-glutamyl Transferase (GGT) Test, Iron Panel, Partial Thromboplastin Time (PTT) Test, Prothrombin Time Test and INR (PT/INR)

Contextual Map

Every relationship of I27.848 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 I27.848 with this related code in Claim Check

Hierarchy

Referenced by Excludes2 notes

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

  • MDC 05 — Diseases and Disorders of the Circulatory System[MDC crossing]: “Diseases and Disorders of the Circulatory System — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 15,708 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027

Index entries

  • Circulation, Fontan related, with, Fontan-associated condition, specified NEC[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Condition, Fontan-associated, specified NEC[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027

Nearest codes (20)

Change history

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 FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
Coding guidelines Official source data
ICD-10-CM Official Guidelines for Coding and Reporting (FY2027), quoted by section Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v44.0 (October 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v44 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

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "I27.848 — Other Fontan-associated condition." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/i27.848-other-fontan-associated-condition

Change history

  • FY2026 — October 1, 2025
    Added to the code set
    Other Fontan-associated condition
    FY2026 changes

Nearest Codes in This Family

Official ICD-10-CM classifications closest to I27.848 in its code family, with their registry titles.

View all codes in the I27 family