2026 ICD-10-CM Diagnosis Code B58.81Toxoplasma myocarditis
ICD-10-CM Codes›A00–B99›B50-B64›B58
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- Not Chronic
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, 791, 793, 974 through 976. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Myocarditis and cardiomyopathy; and Parasitic, other specified and unspecified infections.
Code Identity
Code Classification
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.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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.
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Convert B58.81 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About B58.81Overview
What is the ICD-10 code for toxoplasma myocarditis?
The ICD-10-CM code for toxoplasma myocarditis is B58.81 (sometimes written as B5881). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
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, 791, 793, 974, 975, 976, with relative weights from 0.6821 to 4.1696 depending on complications. Higher weights mean higher Medicare reimbursement.
Is B58.81 a CC or MCC?
CMS lists B58.81 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 B58.81?
Under the General Equivalence Mappings, toxoplasma myocarditis converts to ICD-9-CM 130.3 (toxoplasma myocarditis). The mapping is a direct match.
