2027 ICD-10-CM Diagnosis Code I51.3Intracardiac thrombosis, not elsewhere classified

ICD-10-CM Codes›I00–I99›I30-I5A›I51

ICD-10-CM I51.3
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

I51.3 is a billable ICD-10-CM diagnosis code for intracardiac thrombosis, not elsewhere classified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 302 through 303. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other and ill-defined heart disease.

Code Identity

ICD-10-CM Code
I51.3
Billable Status
Yes — Valid for Submission
Code Describes
Intracardiac thrombosis, not elsewhere classified
Short Description
Intracardiac thrombosis, not elsewhere classified
Same as the full description in the CMS dataset.
Parent Code
I51
Complications and ill-defined descriptions of heart disease

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI30-I5AOther forms of heart disease
CategoryI51Complications and ill-defined descriptions of heart disease
This CodeI51.3Intracardiac thrombosis, not elsewhere classified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Arterial obstruction due to nonthrombotic embolism from heart
  • Arterial obstruction due to thrombotic embolism from mural thrombus of heart
  • Atrial thrombosis
  • Disorder of left atrium as complication of procedure
  • Disorder of right atrium as complication of procedure
  • Intracardiac thrombosis in low output state
  • Left ventricular thrombus
  • Mural thrombus of atrium of heart
  • Mural thrombus of heart
  • Mural thrombus of left atrium
  • Mural thrombus of left ventricle
  • Mural thrombus of right atrium
  • Mural thrombus of right ventricle
  • Mural thrombus of ventricle of heart
  • Occlusion of cutaneous microvasculature structure by cardiac embolus
  • Occlusion of microvasculature of skin caused by embolus
  • Post-infarction mural thrombus
  • Right ventricular thrombus
  • Thromboembolism due to mural thrombus
  • Thrombotic embolism from cardiac atrium
  • Thrombotic embolism from cardiac ventricle
  • Thrombus of cardiac chamber
  • Thrombus of left atrium
  • Thrombus of physiologic left atrium as complication of procedure
  • Thrombus of physiologic right atrium as complication of procedure
  • Thrombus of right atrium

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to I51.3: its own notes plus those printed at I51 and Chapter 9. A note printed at a category, block or chapter applies to every code under it.

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Apical thrombosis (old)
  • Atrial thrombosis (old)
  • Auricular thrombosis (old)
  • Mural thrombosis (old)
  • Ventricular thrombosis (old)

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

  • intracardiac thrombosis as current complication following acute myocardial infarction (I23.6)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From I51 Complications and ill-defined descriptions of heart disease applies to 10 codes
  • heart disease specified as rheumatic (I00-I09)
From Chapter 9 (I00-I99) Diseases of the circulatory system applies to 1,433 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
  • systemic connective tissue disorders (M30-M36)
  • transient cerebral ischemic attacks and related syndromes (G45.-)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name I51.3, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming I51.3: they are not reported together with it, unless the two conditions are unrelated.

  • I23.6 Thrombosis of atrium, auricular appendage, and ventricle as current complications following acute myocardial infarction
    thrombosis of atrium, auricular appendage, and ventricle not specified as current complication following acute myocardial infarction (I51.3)

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR CIR015
Other and ill-defined heart disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Coronary Artery Disease

Coronary artery disease (CAD) is the most common type of heart disease in the United States and a leading cause of death for both men and women.

The full article covers:

  • What is coronary artery disease?
  • What causes coronary artery disease?
  • What are the types of coronary artery disease?
  • Who is more likely to have coronary artery disease?
  • What are symptoms of coronary artery disease?
  • What other problems does coronary artery disease cause?
  • How is coronary artery disease diagnosed?
  • What are the treatments for coronary artery disease?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert I51.3 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
429.89 Ill-defined hrt dis NEC
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About I51.3Overview

What is the ICD-10 code for intracardiac thrombosis, not elsewhere classified?

The ICD-10-CM code for intracardiac thrombosis, not elsewhere classified is I51.3 (sometimes written as I513). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is I51.3 (Complications and ill-defined descriptions of heart disease) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report intracardiac thrombosis, not elsewhere classified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does I51.3 group to?

When intracardiac thrombosis, not elsewhere classified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 302, 303, with relative weights from 0.6610 to 1.1993 depending on complications. Higher weights mean higher Medicare reimbursement.

Can I51.3 be reported with I23.6?

Not as a rule. The Excludes1 note on I51.3 lists "intracardiac thrombosis as current complication following acute myocardial infarction (I23.6)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

What is the ICD-9 equivalent of I51.3?

Under the General Equivalence Mappings, intracardiac thrombosis, not elsewhere classified converts to ICD-9-CM 429.89 (ill-defined hrt dis NEC). The mapping is approximate, so confirm the match fits the documentation.