ICD-10-CM Code B03


Version 2020 Billable Code

Valid for Submission

B03 is a billable code used to specify a medical diagnosis of smallpox. The code is valid for the year 2020 for the submission of HIPAA-covered transactions. The ICD-10-CM code B03 might also be used to specify conditions or terms like alastrim, flat-type smallpox, hemorrhagic smallpox, modified smallpox, smallpox, smallpox without rash, etc

Short Description:Smallpox
Long Description:Smallpox

Tabular List of Diseases and Injuries

The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with guidance for inclusions, exclusions, descriptions and more. The following references are applicable to the code B03:

  • In 1980 the 33rd World Health Assembly declared that smallpox had been eradicated.
  • The classification is maintained for surveillance purposes.

Index to Diseases and Injuries

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code B03 are found in the index:


The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Alastrim
  • Flat-type smallpox
  • Hemorrhagic smallpox
  • Modified smallpox
  • Smallpox
  • Smallpox without rash
  • Variola major

Clinical Information

  • SMALLPOX-. an acute highly contagious often fatal infectious disease caused by an orthopoxvirus characterized by a biphasic febrile course and distinctive progressive skin eruptions. vaccination has succeeded in eradicating smallpox worldwide. dorland 28th ed
  • SMALLPOX VACCINE-. a live vaccinia virus vaccine of calf lymph or chick embryo origin used for immunization against smallpox. it is now recommended only for laboratory workers exposed to smallpox virus. certain countries continue to vaccinate those in the military service. complications that result from smallpox vaccination include vaccinia secondary bacterial infections and encephalomyelitis. dorland 28th ed
  • VARIOLA VIRUS-. a species of orthopoxvirus causing infections in humans. no infections have been reported since 1977 and the virus is now believed to be virtually extinct.

Diagnostic Related Groups

The ICD-10 code B03 is grouped in the following groups for version MS-DRG V37.0 What are Diagnostic Related Groups?
The Diagnostic Related Groups (DRGs) are a patient classification scheme which provides a means of relating the type of patients a hospital treats. The DRGs divides all possible principal diagnoses into mutually exclusive principal diagnosis areas referred to as Major Diagnostic Categories (MDC).
applicable from 10/01/2019 through 09/30/2020.


Convert B03 to ICD-9

  • 050.0 - Variola major (Approximate Flag)
  • 050.1 - Alastrim (Approximate Flag)
  • 050.9 - Smallpox NOS (Approximate Flag)

Code Classification

  • Certain infectious and parasitic diseases (A00–B99)
    • Viral infections characterized by skin and mucous membrane lesions (B00-B09)
      • Smallpox (B03)

Code History

  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016
    (First year ICD-10-CM implemented into the HIPAA code set)
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020

Information for Patients


Smallpox is a disease caused by the Variola major virus. Some experts say that over the centuries it has killed more people than all other infectious diseases combined. Worldwide immunization stopped the spread of smallpox three decades ago. The last case was reported in 1977. Two research labs still keep small amounts of the virus. Experts fear bioterrorists could use the virus to spread disease.

Smallpox spreads very easily from person to person. Symptoms are flu-like. They include

  • High fever
  • Fatigue
  • Headache
  • Backache
  • A rash with flat red sores

There is no treatment. Fluids and medicines for pain or fever can help control symptoms. Most people recover, but some can die. Those who do recover may have severe scars.

The U.S. stopped routine smallpox vaccinations in 1972. Military and other high-risk groups continue to get the vaccine. The U.S. has increased its supply of the vaccine in recent years. The vaccine makes some people sick, so doctors save it for those at highest risk of disease.

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