2027 ICD-10-CM Diagnosis Code B58.2Toxoplasma meningoencephalitis
ICD-10-CM Codes›A00–B99›B50-B64›B58
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- Risk Adjusts — HCC 6
- Not Chronic
B58.2 is a billable ICD-10-CM diagnosis code for toxoplasma meningoencephalitis. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 23 through 24, 97 through 99, 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. Coders also document this condition as acquired disseminated toxoplasmosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Encephalitis; and Parasitic, other specified and unspecified infections.
For Medicare Advantage risk adjustment, B58.2 maps to CMS-HCC Category 6 (Opportunistic Infections) under the V28 model, adding a risk factor of about 0.381 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
B58.2 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Acquired disseminated toxoplasmosis
- Meningoencephalitis due to acquired toxoplasmosis
- Multisystemic disseminated toxoplasmosis
- Toxoplasma encephalitis
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to B58.2: 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 B58.2, its category, or a range that includes it.
Applicable To 1
These notes mention B58.2.
- O98.6 Protozoal diseases complicating pregnancy, childbirth and the puerperium
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Meningoencephalitis See Also: Encephalitis; G04.90
Meningoencephalomyelitis See Also: Meningoencephalitis;
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
Encephalitis
Encephalitis is inflammation (swelling) of the brain. It can happen when an infection or medical condition that affects the brain activates your immune system. The inflammation can cause a wide range of symptoms. In extreme cases, it can lead to brain damage, stroke, or even death.
The full article covers:
- What is encephalitis?
- What causes encephalitis?
- Who is more likely to get encephalitis?
- What are the symptoms of encephalitis?
- How is encephalitis diagnosed?
- What are the treatments for encephalitis?
- Can encephalitis be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert B58.2 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About B58.2Overview
What is the ICD-10 code for toxoplasma meningoencephalitis?
The ICD-10-CM code for toxoplasma meningoencephalitis is B58.2 (sometimes written as B582). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is B58.2 (Toxoplasmosis) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report toxoplasma meningoencephalitis on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does B58.2 group to?
When toxoplasma meningoencephalitis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 793, 791, 24, 98, 974, 976, 99, 975, 23, 97, with relative weights from 0.7879 to 5.7422 depending on complications. Higher weights mean higher Medicare reimbursement.
Is B58.2 a CC or MCC?
CMS lists B58.2 as an MCC (major complication or comorbidity) for FY 2027. 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.
Can B58.2 be reported with P37.1?
Not as a rule. The Excludes1 note at B58, which applies to B58.2, 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).
What HCC is B58.2?
B58.2 (toxoplasma meningoencephalitis) maps to CMS-HCC Category 6 (Opportunistic Infections), commonly written as HCC 6, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 6 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 5.
Does B58.2 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, B58.2 adds a risk adjustment factor of about 0.381 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.381 to 0.833 depending on the payment segment). HCC 6 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 6 category page.
