2027 ICD-10-CM Diagnosis Code B58.9Toxoplasmosis, unspecified
ICD-10-CM Codes›A00–B99›B50-B64›B58
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Not Chronic
B58.9 is a billable ICD-10-CM diagnosis code for toxoplasmosis, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 867 through 869, 974 through 976. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 1 closely related codes. 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
Code Classification
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
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to B58.9: its own notes plus those printed at B58, block B50-B64, and Chapter 1. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- infection due to Toxoplasma gondii
- diseases generally recognized as communicable or transmissible
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- carrier or suspected carrier of infectious disease (Z22.-)
- certain localized infections - see body system-related chapters
- infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
- infectious and parasitic diseases specific to the perinatal period (P35-P39)
- influenza and other acute respiratory infections (J00-J22)
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- code to identify resistance to antimicrobial drugs (Z16.-)
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name B58.9, its category, or a range that includes it.
Applicable To 1
These notes mention B58.9.
- O98.6 Protozoal diseases complicating pregnancy, childbirth and the puerperium
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
Toxoplasmosis
the acquired form of infection by toxoplasma gondii in animals and man.
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.
Code HistoryHistory
Questions About B58.9Overview
What is the ICD-10 code for toxoplasmosis, unspecified?
The ICD-10-CM code for toxoplasmosis, unspecified is B58.9 (sometimes written as B589). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
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, 2026 through September 30, 2027.
What MS-DRG does B58.9 group to?
When toxoplasmosis, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 974, 976, 975, 867, 869, 868, with relative weights from 0.6784 to 3.0488 depending on complications. Higher weights mean higher Medicare reimbursement.
Is B58.9 a CC or MCC?
CMS lists B58.9 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 1 closely related codes in its exclusion list.
Can B58.9 be reported with P37.1?
Not as a rule. The Excludes1 note at B58, which applies to B58.9, lists "congenital toxoplasmosis (P37.1)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
