2026 ICD-10-CM Diagnosis Code B58.81Toxoplasma myocarditis

ICD-10-CM Codes›A00–B99›B50-B64›B58

ICD-10-CM B58.81
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

B58.81 is a billable ICD-10-CM diagnosis code for toxoplasma myocarditis. 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, 974 through 976. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Myocarditis and cardiomyopathy; and Parasitic, other specified and unspecified infections.

Code Identity

ICD-10-CM Code
B58.81
Billable Status
Yes — Valid for Submission
Code Describes
Toxoplasma myocarditis
Short Description
Toxoplasma myocarditis
Same as the full description in the CMS dataset.
Parent Code
B58.8
Toxoplasmosis with other organ involvement

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionB50-B64Protozoal diseases
CategoryB58Toxoplasmosis
This CodeB58.81Toxoplasma myocarditis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acquired disseminated toxoplasmosis
  • Acute myocarditis
  • Acute myocarditis - toxoplasmosis
  • Multisystemic disseminated toxoplasmosis
  • Myocarditis due to acquired toxoplasmosis
  • Parasitic myocarditis
  • Protozoan myocarditis
  • Toxoplasma myocarditis

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Myocarditis(with arteriosclerosis)(chronic)(fibroid) (interstitial) (old) (progressive) (senile)
      • in (due to)
        • toxoplasmosis (acquired)

Clinical ClassificationClinical

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

CCSR CIR005
Myocarditis and cardiomyopathy
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR INF009
Parasitic, other specified and unspecified infections
Default principal diagnosis: inpatient No · outpatient No

Clinical InformationClinical

  • Acute Myocarditis

    the sudden onset of inflammation of heart muscle with myocellular necrosis; this is generally secondary to an infectious cause, and patients often have a recent history of a flu-like illness.

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

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

Convert B58.81 to ICD-9-CMHistory

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

ICD-9-CM
130.3 Toxoplasma myocarditis
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 B58.81Overview

Is B58.81 (Toxoplasmosis with other organ involvement) a billable code?

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

What MS-DRG does B58.81 group to?

When toxoplasma myocarditis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 314, 315, 316, 974, 975, 976, with relative weights from 0.6821 to 2.8860 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of B58.81?

Under the General Equivalence Mappings, toxoplasma myocarditis converts to ICD-9-CM 130.3 (toxoplasma myocarditis). The mapping is a direct match.

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.