2027 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 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

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
Short Description
Other and unspecified infectious diseases
Same as the full description in the CMS dataset.
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

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to B99: 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, its category, or a range that includes it.

Applicable To 2

These notes mention B99.

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

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About B99Overview

What is the ICD-10 code for other and unspecified infectious diseases?

B99 is the ICD-10-CM category for other and unspecified infectious diseases, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

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

No. This 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.