2026 ICD-10-CM Diagnosis Code B58.82Toxoplasma myositis

ICD-10-CM Codes›A00–B99›B50-B64›B58

ICD-10-CM B58.82
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

B58.82 is a billable ICD-10-CM diagnosis code for toxoplasma myositis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 867 through 869, 974 through 976. Coders also document this condition as parasitic myositis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Muscle disorders; and Parasitic, other specified and unspecified infections.

Code Identity

ICD-10-CM Code
B58.82
Billable Status
Yes — Valid for Submission
Code Describes
Toxoplasma myositis
Short Description
Toxoplasma myositis
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 CodeB58.82Toxoplasma myositis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Parasitic myositis
  • Protozoal myositis
  • Toxoplasma myositis

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.

    • Myositis
      • in (due to)
        • toxoplasmosis (acquired)

Clinical ClassificationClinical

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

CCSR MUS026
Muscle disorders
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR INF009
Parasitic, other specified and unspecified infections
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Myositis

Myositis means inflammation of the muscles that you use to move your body. An injury, infection, or autoimmune disease can cause it. Two specific kinds are polymyositis and dermatomyositis. Polymyositis causes muscle weakness, usually in the muscles closest to the trunk of your body.

Read the full article at MedlinePlus

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

Convert B58.82 to ICD-9-CMHistory

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

ICD-9-CM
130.7 Toxoplasmosis site NEC
Approximate The match is approximate rather than exact.

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 B58.82Overview

Is B58.82 (Toxoplasmosis with other organ involvement) a billable code?

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

What MS-DRG does B58.82 group to?

When toxoplasma myositis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 867, 868, 869, 974, 975, 976, with relative weights from 0.7297 to 2.8860 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of B58.82?

Under the General Equivalence Mappings, toxoplasma myositis converts to ICD-9-CM 130.7 (toxoplasmosis site NEC). 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.