2026 ICD-10-CM Diagnosis Code I39Endocarditis and heart valve disorders in diseases classified elsewhere
ICD-10-CM Codes›I00–I99›I30-I5A›I39
- Billable — Valid for Submission
- Not Chronic
I39 is a billable ICD-10-CM diagnosis code for endocarditis and heart valve disorders in diseases classified elsewhere. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 306 through 307. The code is a manifestation code that cannot be reported as the principal diagnosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Endocarditis and endocardial disease.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for I39.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Abnormality of atrioventricular valve leaflet in atrioventricular septal defect
- Abnormality of common atrioventricular valve chordae tendinae
- Abnormality of common atrioventricular valve in atrioventricular septal defect
- Abnormality of common atrioventricular valve papillary muscle
- Abnormality of left atrioventricular valve chordae tendinae
- Abnormality of left atrioventricular valve in double inlet ventricle
- Abnormality of right atrioventricular valve chordae tendinae
- Abnormality of right atrioventricular valve in double inlet ventricle
- Abnormality of truncal valve cusp
- Accessory tissue on common atrioventricular valve leaflet
- Accessory tissue on left atrioventricular valve leaflet
- Accessory tissue on right atrioventricular valve leaflet
- African histoplasmosis
- Arcade abnormality of common atrioventricular valve chordae
- Arcade abnormality of left atrioventricular valve chordae
- Common atrioventricular valve chordae too long
- Common atrioventricular valve leaflet abnormality
- Common atrioventricular valve limited to one ventricle
- Common atrioventricular valve stenosis
- Congenital abnormality of left atrioventricular valve papillary muscle
- Congenital abnormality of right atrioventricular valve papillary muscle
- Deficiency of truncal valve cusp
- Double orifice of left atrioventricular valve
- Double orifice of right atrioventricular valve
- Dysplasia of common atrioventricular valve
- Endocarditis associated with another disorder
- Fenestration of atrioventricular valve leaflet in atrioventricular septal defect
- Fenestration of truncal valve cusp
- Histoplasma capsulatum with endocarditis
- Histoplasma duboisii with endocarditis
- Hypoplasia of common atrioventricular valve
- Hypoplastic common atrioventricular valve papillary muscle
- Left atrioventricular valve chordae to outlet septum
- Left atrioventricular valve chordae too long
- Left atrioventricular valve chordae too short
- Left atrioventricular valve dysplasia
- Left atrioventricular valve hypoplasia
- Left atrioventricular valve leaflet abnormality
- Left atrioventricular valve leaflet dysplasia
- Left atrioventricular valve prolapse
- Left atrioventricular valve stenosis
- Mycotic endocarditis
- Quadricuspid truncal valve
- Regurgitation of common atrioventricular valve
- Right atrioventricular valve chordae to outlet septum
- Right atrioventricular valve dysplasia
- Right atrioventricular valve hypoplasia
- Right atrioventricular valve leaflet abnormality
- Right atrioventricular valve stenosis
- Straddling left atrioventricular valve
- Straddling right atrioventricular valve
- Tricuspid truncal valve
- Triple orifice of left ventricular component of common atrioventricular valve
- Truncal valve prolapse
- Truncal valve regurgitation
- Truncal valve stenosis
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Code First
- underlying disease, such as:
- Q fever A78
Type 1 Excludes
- endocardial involvement in:
- candidiasis B37.6
- gonococcal infection A54.83
- Libman-Sacks disease M32.11
- listerosis A32.82
- meningococcal infection A39.51
- rheumatoid arthritis M05.31
- syphilis A52.03
- tuberculosis A18.84
- typhoid fever A01.02
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
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).
The full article covers:
- What is endocarditis?
- What causes endocarditis?
- Who is more likely to develop endocarditis?
- What are the symptoms of endocarditis?
- What other problems can endocarditis cause?
- How is endocarditis diagnosed?
- What are the treatments for endocarditis?
- Can endocarditis be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert I39 to ICD-9-CMHistory
Code HistoryHistory
Questions About I39Overview
Is I39 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report endocarditis and heart valve disorders in diseases classified elsewhere on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does I39 group to?
On inpatient claims, endocarditis and heart valve disorders in diseases classified elsewhere maps to MS-DRG 306, 307, with relative weights from 0.9132 to 1.5758 depending on complications. Higher weights mean higher Medicare reimbursement.
Can I39 be a principal diagnosis?
No. This is a manifestation code: endocarditis and heart valve disorders in diseases classified elsewhere describes the manifestation of an underlying disease rather than the disease itself, so the underlying condition is sequenced first.
What is the ICD-9 equivalent of I39?
Under the General Equivalence Mappings, endocarditis and heart valve disorders in diseases classified elsewhere converts to ICD-9-CM 421.1 (ac endocardit in oth dis) and 424.91 (endocarditis in oth dis). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
