2026 ICD-10-CM Diagnosis Code B58.9Toxoplasmosis, unspecified

ICD-10-CM Codes›A00–B99›B50-B64›B58

ICD-10-CM B58.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

B58.9 is a billable ICD-10-CM diagnosis code for toxoplasmosis, unspecified. 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 coccidiosis co-occurrent with human immunodeficiency virus infection. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Parasitic, other specified and unspecified infections.

Code Identity

ICD-10-CM Code
B58.9
Billable Status
Yes — Valid for Submission
Code Describes
Toxoplasmosis, unspecified
Short Description
Toxoplasmosis, unspecified
Same as the full description in the CMS dataset.
Parent Code
B58
Toxoplasmosis

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionB50-B64Protozoal diseases
CategoryB58Toxoplasmosis
This CodeB58.9Toxoplasmosis, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Coccidiosis co-occurrent with human immunodeficiency virus infection
  • Infection caused by Coccidia co-occurrent with acquired immunodeficiency syndrome
  • Infection caused by Toxoplasma
  • Infection caused by Toxoplasma gondii co-occurrent with acquired immunodeficiency syndrome
  • Infectious mononucleosis caused by Toxoplasma
  • Multisystemic disseminated toxoplasmosis
  • Toxoplasmosis
  • Toxoplasmosis of multiple sites

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.

    • Toxoplasma, toxoplasmosis(acquired)

Clinical ClassificationClinical

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

CCSR INF009
Parasitic, other specified and unspecified infections
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Toxoplasmosis

    the acquired form of infection by toxoplasma gondii in animals and man.

  • Toxoplasmosis, Animal

    acquired infection of non-human animals by organisms of the genus toxoplasma.

  • Toxoplasmosis, Cerebral

    infections of the brain caused by the protozoan toxoplasma gondii that primarily arise in individuals with immunologic deficiency syndromes (see also aids-related opportunistic infections). the infection may involve the brain diffusely or form discrete abscesses. clinical manifestations include seizures, altered mentation, headache, focal neurologic deficits, and intracranial hypertension. (from joynt, clinical neurology, 1998, ch27, pp41-3)

  • Toxoplasmosis, Congenital

    prenatal protozoal infection with toxoplasma gondii which is associated with injury to the developing fetal nervous system. the severity of this condition is related to the stage of pregnancy during which the infection occurs; first trimester infections are associated with a greater degree of neurologic dysfunction. clinical features include hydrocephalus; microcephaly; deafness; cerebral calcifications; seizures; and psychomotor retardation. signs of a systemic infection may also be present at birth, including fever, rash, and hepatosplenomegaly. (from adams et al., principles of neurology, 6th ed, p735)

  • Toxoplasmosis, Ocular

    infection caused by the protozoan parasite toxoplasma in which there is extensive connective tissue proliferation, the retina surrounding the lesions remains normal, and the ocular media remain clear. chorioretinitis may be associated with all forms of toxoplasmosis, but is usually a late sequel of congenital toxoplasmosis. the severe ocular lesions in infants may lead to blindness.

  • Toxoplasma

    a genus of protozoa parasitic to birds and mammals. t. gondii is one of the most common infectious pathogenic animal parasites of man.

  • AIDS-Related Toxoplasmosis

    toxoplasmosis associated with aids.

  • Adult Acquired Toxoplasmosis

    toxoplasmosis acquired in adulthood.

  • Aicardi-Goutieres Syndrome 1|AGS1|Cree Encephalitis|Encephalopathy, Familial Infantile, with Intracranial Calcification and Chronic Cerebrospinal Fluid Lymphocytosis|Pseudotoxoplasmosis Syndrome

    a heritable condition, caused by mutation(s) in the trex1 gene, encoding three-prime repair exonuclease 1. clinical features and onset may vary significantly, but is characterized in its most severe form by cerebral atrophy, leukodystrophy, intracranial calcifications, chronic cerebrospinal fluid (csf) lymphocytosis, and increased concentrations of csf alpha-interferon.

  • Congenital Toxoplasmosis

    toxoplasma infection that is present from birth.

  • Cordonnier Grade 2 Parasitic Complication, Toxoplasmosis Infection without Organ Involvement|Cordonnier Grade 2 Parasitic Complication|Grade 2 Toxoplasmosis Infection without Organ Involvement

    any toxoplasmosis infection without organ involvement.

  • Cordonnier Grade 3 Parasitic Complication, Central Nervous System or Other Organ Toxoplasmosis|Grade 3 CNS or Other Organ Toxoplasmosis

    any toxoplasmosis infection with central nervous system involvement or other organ involvement.

  • Nephrotic Syndrome - Toxoplasmosis Associated|Toxoplasmosis Associated Nephrotic Syndrome

    nephrotic syndrome associated with a toxoplasmosis infection.

  • TORCH Antibody Measurement|Toxoplasmosis, Other Infections, Rubella, Cytomegalovirus, and Herpes Simplex Virus (TORCH) Antibody Panel Measurement

    a group of blood tests used to detect antibodies to toxoplasma gondii, rubella, cytomegalovirus, and herpes simplex virus to rule out congenital infections. a group of other infections may be tested as well, including varicella-zoster virus, hepatitis b virus, human immunodeficiency virus, parvovirus b19, and syphilis.

  • TORCH Syndrome|TORCH Infection|Toxoplasmosis, Other Infections, Rubella, Cytomegalovirus, and Herpes Simplex Virus (TORCH) Syndrome

    a syndrome that results from a group of infections that affect the fetus or the newborn. the group of infections includes toxoplasma gondii, rubella, cytomegalovirus, herpes simplex virus, and other infections. the other infections include varicella-zoster virus, hepatitis b virus, human immunodeficiency virus, parvovirus b19, and syphilis. signs and symptoms include fever, feeding difficulties, petechial rash, jaundice, hepatosplenomegaly, chorioretinitis, and microcephaly.

  • Toxoplasmosis

    a parasitic disease contracted by the ingestion or fetal transmission of toxoplasma gondii.

Patient EducationClinical

Toxoplasmosis

Toxoplasmosis is a disease caused by the parasite Toxoplasma gondii. More than 60 million people in the U.S. have the parasite. Most of them don't get sick. But the parasite causes serious problems for some people. These include people with weak immune systems and babies whose mothers become infected for the first time during pregnancy.

Read the full article at MedlinePlus

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

Convert B58.9 to ICD-9-CMHistory

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

ICD-9-CM
130.9 Toxoplasmosis 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 B58.9Overview

Is B58.9 (Toxoplasmosis) a billable code?

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

What MS-DRG does B58.9 group to?

When toxoplasmosis, unspecified 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 B58.9?

Under the General Equivalence Mappings, toxoplasmosis, unspecified converts to ICD-9-CM 130.9 (toxoplasmosis NOS). 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.