Is ICD-10-CM code B33 billable?

No, B33 (Other viral diseases, not elsewhere classified) 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 B33 belong to?

B33 belongs to Chapter 1 of the ICD-10-CM tabular list: A00–B99 (Certain Infectious and Parasitic Diseases).

B33Not billable, use a more specific code below

Other viral diseases, not elsewhere classified

In Other viral diseases (B25-B34), chapter 1: Certain Infectious and Parasitic Diseases

10 billable codes under B33: 6 are a CC; 1 map to HCC 227 (Cardiomyopathy/Myocarditis).A CC or MCC (major CC) is a secondary diagnosis that raises the MS-DRG payment. An HCC counts toward a Medicare Advantage patient's risk score.

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 B33

B33 can't be used on a claim. Pick a billable code below; grey headings group them.

B33 MS-DRGs

As the principal diagnosis, the billable codes under B33 group to these 10 MS-DRGs (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.

DRG 314 Other Circulatory System Diagnoses with MCC (4 of 10 codes)
DRG 315 Other Circulatory System Diagnoses with CC (4 of 10 codes)
DRG 316 Other Circulatory System Diagnoses without CC/MCC (4 of 10 codes)
DRG 865 Viral Illness with MCC (4 of 10 codes)
DRG 866 Viral Illness without MCC (4 of 10 codes)
DRG 193 Simple Pneumonia and Pleurisy with MCC (1 of 10 codes)
DRG 194 Simple Pneumonia and Pleurisy with CC (1 of 10 codes)
DRG 195 Simple Pneumonia and Pleurisy without CC/MCC (1 of 10 codes)
DRG 306 Cardiac Congenital and Valvular Disorders with MCC (1 of 10 codes)
DRG 307 Cardiac Congenital and Valvular Disorders without MCC (1 of 10 codes)

About the condition

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

Viral Infections

Viruses are very tiny germs. They are made of genetic material (either DNA or RNA) inside of a protein coating. There are a huge number of viruses on earth. Only a small number of them can infect humans. Those viruses can infect our cells, which may cause disease. Some of the diseases that viruses can cause include the common cold, the flu, COVID-19, and HIV.

Code history

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