2026 ICD-10-CM Diagnosis Code B99Other and unspecified infectious diseases

ICD-10-CM Codes›A00–B99›B99›B99

ICD-10-CM B99
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

B99 is a non-billable ICD-10-CM category code for other and unspecified infectious diseases, so it cannot be submitted on claims. Use a more specific code from this category instead, such as B99.8 and B99.9.

Code Identity

ICD-10-CM Code
B99
Billable Status
No — Non-Billable Category
Code Describes
Other and unspecified infectious diseases
Chapter
B99
Other infectious diseases

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionB99Other infectious diseases
CategoryB99Other and unspecified infectious diseases
This CodeB99Other and unspecified infectious diseases

Specific Coding for Other and unspecified infectious diseasesOverview

Non-specific codes like B99 require more characters. Use one of these billable codes instead:

  • Use B99.8 for Other infectious disease

  • Use B99.9 for Unspecified infectious disease

Questions About B99Overview

Is B99 a billable code?

No. B99 is a category header that groups the codes for other and unspecified infectious diseases, and headers cannot be submitted on claims. Claims for other and unspecified infectious diseases need a more specific code from this category, such as B99.8 and B99.9.

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.

    • Arthropathy
      • postinfectious NEC
    • Conjunctivitis(staphylococcal) (streptococcal) NOS
      • in (due to)
        • infectious disease NEC
    • Encephalitis(chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute)
      • in (due to)
        • infectious disease NEC
    • Iridocyclitis
      • in (due to)
        • infectious disease NOS
    • Mastoiditis(coalescent) (hemorrhagic) (suppurative)
      • in (due to)
        • infectious disease NEC
    • Myopathy
      • in (due to)
        • infectious disease NEC
    • Neuritis(rheumatoid)
      • acoustic (nerve)
        • in (due to)
          • infectious disease NEC
    • Otitis(acute)
      • externa
        • in (due to)
          • infectious disease NEC
    • Palsy
      • cranial nerve
        • multiple
          • in
            • infectious disease
    • Pneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)
      • postinfectional NEC
    • Polyneuropathy(peripheral)
      • in (due to)
        • infectious
          • disease NEC

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.

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.