2026 ICD-10-CM Diagnosis Code A39.50Meningococcal carditis, unspecified

ICD-10-CM Codes›A00–B99›A30-A49›A39

ICD-10-CM A39.50
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A39.50 is a billable ICD-10-CM diagnosis code for meningococcal carditis, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 314 through 316, 791, 793. As a secondary diagnosis, it counts as a major complication or comorbidity (MCC) and places an inpatient stay in the highest severity level of its MS-DRG family. It does not count, however, when the principal diagnosis is one of 10 closely related codes. Coders also document this condition as meningococcal carditis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections and Myocarditis and cardiomyopathy.

Code Identity

ICD-10-CM Code
A39.50
Billable Status
Yes — Valid for Submission
Code Describes
Meningococcal carditis, unspecified
Short Description
Meningococcal carditis, unspecified
Same as the full description in the CMS dataset.
Parent Code
A39.5
Meningococcal heart disease

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA30-A49Other bacterial diseases
CategoryA39Meningococcal infection
This CodeA39.50Meningococcal carditis, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Meningococcal carditis

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 INF003
Bacterial infections
Default principal diagnosis: inpatient No · outpatient No
CCSR CIR005
Myocarditis and cardiomyopathy
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Cardiomyopathy

Cardiomyopathy is the name for diseases of the heart muscle. These diseases enlarge your heart muscle or make it thicker and more rigid than normal. In rare cases, scar tissue replaces the muscle tissue.

Read the full article at MedlinePlus

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Convert A39.50 to ICD-9-CMHistory

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

ICD-9-CM
036.40 Meningococc carditis NOS
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About A39.50Overview

What is the ICD-10 code for meningococcal carditis, unspecified?

The ICD-10-CM code for meningococcal carditis, unspecified is A39.50 (sometimes written as A3950). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is A39.50 (Meningococcal heart disease) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report meningococcal carditis, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does A39.50 group to?

When meningococcal carditis, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 314, 315, 316, 791, 793, with relative weights from 0.6821 to 4.1696 depending on complications. Higher weights mean higher Medicare reimbursement.

Is A39.50 a CC or MCC?

CMS lists A39.50 as an MCC (major complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it places the inpatient stay in the highest-weighted DRG of its severity family. It does not count when the principal diagnosis is one of the 10 closely related codes in its exclusion list.

What is the ICD-9 equivalent of A39.50?

Under the General Equivalence Mappings, meningococcal carditis, unspecified converts to ICD-9-CM 036.40 (meningococc carditis NOS). The mapping is a direct match.