Is ICD-10-CM code B99 billable?

No, B99 (Other and unspecified infectious diseases) is a non-billable ICD-10-CM code. It must be coded to a more specific subcategory before it can be used for reimbursement.

What chapter does ICD-10-CM code B99 belong to?

B99 belongs to Chapter 1 of the ICD-10-CM tabular list: A00–B99 (Certain Infectious and Parasitic Diseases).

B99Not billable, use a more specific code below

Other and unspecified infectious diseases

chapter 1: Certain Infectious and Parasitic Diseases

2 billable codes under B99: none are a CC or MCC; none map to an HCC.

Also indexed as: Arthropathy, postinfectious NEC; Conjunctivitis NOS, in, infectious disease NEC; Encephalitis, in, infectious disease NEC; Iridocyclitis, in, infectious disease NOS; Mastoiditis, in, infectious disease NEC; Myopathy, in, infectious disease NEC; Neuritis, acoustic, in, infectious disease NEC; Otitis, externa, in, infectious disease NEC; Palsy, cranial nerve, multiple, in, infectious disease; Pneumonia, postinfectional NEC; Polyneuropathy, in, infectious, disease NEC

Official coding guidelines

From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.

Rules for coding infections and parasitic diseases, including HIV, organism and drug resistance codes, sepsis and septic shock, MRSA, Zika, and COVID-19.

Human Immunodeficiency Virus (HIV) Infections (page 19)
Infectious agents as the cause of diseases classified to other chapters (page 22)
Infections resistant to antibiotics (page 22)
Sepsis, Severe Sepsis, and Septic Shock (page 23)
Methicillin Resistant Staphylococcus aureus (MRSA) Conditions (page 27)
Zika virus infections (page 28)
Coronavirus infections (page 28)

Read Section I.C.1 (page 19)

All codes under B99

B99 can't be used on a claim. Pick a billable code below; grey headings group them.

B99 MS-DRGs

As the principal diagnosis, the billable codes under B99 group to these 9 MS-DRGs (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.

DRG 867 Other Infectious and Parasitic Diseases Diagnoses with MCC (2 of 2 codes)
DRG 868 Other Infectious and Parasitic Diseases Diagnoses with CC (2 of 2 codes)
DRG 869 Other Infectious and Parasitic Diseases Diagnoses without CC/MCC (2 of 2 codes)
DRG 146 Ear, Nose, Mouth and Throat Malignancy with MCC (1 of 2 codes)
DRG 147 Ear, Nose, Mouth and Throat Malignancy with CC (1 of 2 codes)
DRG 148 Ear, Nose, Mouth and Throat Malignancy without CC/MCC (1 of 2 codes)
DRG 974 HIV with Major Related Condition with MCC (1 of 2 codes)
DRG 975 HIV with Major Related Condition with CC (1 of 2 codes)
DRG 976 HIV with Major Related Condition without CC/MCC (1 of 2 codes)

Other codes that refer to B99

Notes on these codes point to B99.

CH10 Excludes2: certain infectious and parasitic diseases (A00-B99)
CH11 Excludes2: certain infectious and parasitic diseases (A00-B99)
CH12 Excludes2: certain infectious and parasitic diseases (A00-B99)
CH13 Excludes2: certain infectious and parasitic diseases (A00-B99)
CH14 Excludes2: certain infectious and parasitic diseases (A00-B99)
CH6 Excludes2: certain infectious and parasitic diseases (A00-B99)
CH7 Excludes2: certain infectious and parasitic diseases (A00-B99)
CH8 Excludes2: certain infectious and parasitic diseases (A00-B99)
CH9 Excludes2: certain infectious and parasitic diseases (A00-B99)
D81.82 Code Also: other infections (A00-B99)
L97 Excludes2: specific infections classified to A00-B99
L98.4 Excludes2: specific infections classified to A00-B99
L98.A Excludes2: specific infections classified to A00-B99
P00.2 Includes: Newborn affected by maternal infectious disease classifiable to A00-B99, J09 and J10
P35-P39 Excludes2: infectious diseases not specific to the perinatal period (A00-B99, J09, J10.-)
Z83.1 Includes: Conditions classifiable to A00-B19, B25-B94, B99
Z86.1 Includes: Conditions classifiable to A00-B89, B99

About the condition

Plain-language background from MedlinePlus (National Library of Medicine), not coding guidance.

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.

Code history

Valid since FY2016, when ICD-10-CM took effect on October 1, 2015. No changes since.