All ICD10 Codes
I39Billable, valid for claims from October 1, 2026

Endocarditis and heart valve disorders in diseases classified elsewhere

In Other forms of heart disease (I30-I5A), chapter 9: Diseases of the Circulatory System

  • I39 is billable and valid on claims for FY 2027. If the record has more detail, check the other codes under I30-I5A below.
  • As a secondary diagnosis it is a CC (complication or comorbidity), which can raise the MS-DRG payment. It doesn't count when the principal diagnosis is one of 8 closely related codes.
  • Doesn't count toward a Medicare Advantage risk score (no HCC in V28).
  • AHRQ's Chronic Condition Indicator classes it as not chronic (an acute or short-term condition).
  • Can't be the principal diagnosis: code the underlying condition first. (Manifestation list)

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Instructional notes

Excludes1: not coded here, use a different code

Code first: code the underlying condition first, then this code

  • underlying disease, such as:
  • Q fever (A78)

Official coding guidelines

From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.

Covers hypertension with heart and kidney disease, coronary artery disease with angina, perioperative stroke, cerebrovascular sequelae, and acute myocardial infarction types and timing.

Read Section I.C.9 (page 50)

Other codes under I30-I5A

Other forms of heart disease (I30-I5A)

I39 MS-DRGs

As the principal diagnosis, I39 groups to MS-DRG 306, 307, 791, or 793 (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.

Related conditions

Grouped by AHRQ's Clinical Classifications Software Refined (CCSR), which sorts every diagnosis code into clinically meaningful categories.

I39 is in Endocarditis and endocardial disease (CIR004), with 18 codes. Others in it:

  • A18.84 Tuberculosis of heart
  • A32.82 Listerial endocarditis
  • A39.51 Meningococcal endocarditis
  • A52.03 Syphilitic endocarditis
  • A52.06 Other syphilitic heart involvement
  • A54.83 Gonococcal heart infection
  • B33.21 Viral endocarditis
  • B37.6 Candidal endocarditis

Medicare coverage articles listing I39

These 9 Medicare billing and coding articles list I39 as a diagnosis that supports medical necessity for the services they cover. From the CMS Medicare Coverage Database; check your own contractor's article before billing.

Other codes that refer to I39

Notes on these codes point to I39.

  • B39 Use Additional Code: endocarditis (I39)

About the condition

Plain-language background from MedlinePlus (National Library of Medicine), not coding guidance.

Endocarditis

Endocarditis is sometimes called infective endocarditis. It's a rare but life-threatening inflammation of the lining inside your heart's chambers and valves (the endocardium).

Read more about endocarditis on MedlinePlus

Heart Valve Diseases

Heart valve disease happens when one or more of your heart valves don't work well. Your heart has four valves: the tricuspid, pulmonary, mitral, and aortic valves. The valves have flaps that open and close. The flaps make sure that blood flows in the right direction through your heart and to the rest of your body. When your heart beats, the flaps open to let blood through. Between heartbeats they close to stop the blood from flowing backwards.

Read more about heart valve diseases on MedlinePlus

Code history

Valid since FY2016, when ICD-10-CM took effect on October 1, 2015. No changes since.

ICD-9-CM equivalent

Legacy crosswalk from the CMS General Equivalence Mappings (last updated 2018).

  • 421.1 Acute and subacute infective endocarditis in diseases classified elsewhere (approximate)
  • 424.91 Endocarditis in diseases classified elsewhere (approximate)
ICD-9 to ICD-10 converter