2027 ICD-10-CM Diagnosis Code B99.8Other infectious disease

ICD-10-CM Codes›A00–B99›B99›B99

ICD-10-CM B99.8
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

B99.8 is a billable ICD-10-CM diagnosis code for other infectious disease. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Parasitic, other specified and unspecified infections.

Code Identity

ICD-10-CM Code
B99.8
Billable Status
Yes — Valid for Submission
Code Describes
Other infectious disease
Short Description
Other infectious disease
Same as the full description in the CMS dataset.
Parent Code
B99
Other and unspecified infectious diseases

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionB99Other infectious diseases
CategoryB99Other and unspecified infectious diseases
This CodeB99.8Other infectious disease

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Dermatosis caused by algae
  • Dust-borne infectious disease
  • Infection - non-suppurative
  • Infection - suppurative
  • Infection by algae
  • Infection by Oomycota
  • Infection by Prototheca segbwema
  • Infection by Prototheca wickerhamii
  • Infection by Prototheca zopfi
  • Infection caused by chordate
  • Infection of cranial nerve
  • Infectious disease caused by plant
  • Mucopyocele
  • Protothecosis
  • Protothecosis of skin

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to B99.8: its own notes plus those printed at 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.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • diseases generally recognized as communicable or transmissible

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.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • 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.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • 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 B99.8, its category, or a range that includes it.

Applicable To 2

These notes mention B99.8.

  • Z83.1 Family history of other infectious and parasitic diseases
    Conditions classifiable to A00-B19, B25-B94, B99 names B99, which includes this code
  • Z86.1 Personal history of infectious and parasitic diseases
    Conditions classifiable to A00-B89, B99 names B99, which includes this code

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.

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

Patient EducationClinical

Infectious Diseases

Germs, or microbes, are found everywhere - in the air, soil, and water. There are also germs on your skin and in your body. Many of them are harmless, and some can even be helpful. But some of them can make you sick. Infectious diseases are diseases that are caused by germs.

The full article covers:

  • What are infectious diseases?
  • What are the different types of germs that cause infectious diseases?
  • How can you get infectious diseases?
  • What are the symptoms of infectious diseases?
  • What are the treatments for infectious diseases?
  • Can infectious diseases be prevented?

Read the full article at MedlinePlus

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

Convert B99.8 to ICD-9-CMHistory

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

ICD-9-CM
136.8 Infect/parasite dis 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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About B99.8Overview

What is the ICD-10 code for other infectious disease?

The ICD-10-CM code for other infectious disease is B99.8 (sometimes written as B998). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is B99.8 (Other and unspecified infectious diseases) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other infectious disease on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does B99.8 group to?

When other infectious disease 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.

What is the ICD-9 equivalent of B99.8?

Under the General Equivalence Mappings, other infectious disease converts to ICD-9-CM 136.8 (infect/parasite dis NEC). The mapping is approximate, so confirm the match fits the documentation.