ICD-10-CM Code B59


Version 2021 Billable Code

Valid for Submission

B59 is a billable code used to specify a medical diagnosis of pneumocystosis. The code is valid for the fiscal year 2021 for the submission of HIPAA-covered transactions. The ICD-10-CM code B59 might also be used to specify conditions or terms like disseminated pneumocystosis, extrapulmonary pneumocystis infection, fungal choroiditis, infection by pneumocystis jirovecii, infection caused by pneumocystis co-occurrent with human immunodeficiency virus infection, infection of lung caused by pneumocystis, etc

Short Description:Pneumocystosis
Long Description:Pneumocystosis

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 B59:

Inclusion Terms

Inclusion Terms
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
  • Pneumonia due to Pneumocystis carinii
  • Pneumonia due to Pneumocystis jiroveci

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 B59 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:

  • Disseminated pneumocystosis
  • Extrapulmonary pneumocystis infection
  • Fungal choroiditis
  • Infection by Pneumocystis jirovecii
  • Infection caused by Pneumocystis co-occurrent with human immunodeficiency virus infection
  • Infection of lung caused by Pneumocystis
  • Pneumocystis jirovecii choroiditis
  • Pneumocystis jirovecii present
  • Pneumocystosis
  • Pneumocystosis
  • Pneumocystosis associated with AIDS
  • Pneumocystosis pneumonia

Clinical Information

  • PNEUMONIA PNEUMOCYSTIS-. a pulmonary disease in humans occurring in immunodeficient or malnourished patients or infants characterized by dyspnea tachypnea and hypoxemia. pneumocystis pneumonia is a frequently seen opportunistic infection in aids. it is caused by the fungus pneumocystis jirovecii. the disease is also found in other mammals where it is caused by related species of pneumocystis.

Diagnostic Related Groups

The ICD-10 code B59 is grouped in the following groups for version MS-DRG V38.0 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 10/01/2020 through 09/30/2021.


Convert B59 to ICD-9

Code Classification

  • Certain infectious and parasitic diseases (A00–B99)
    • Protozoal diseases (B50-B64)
      • Pneumocystosis (B59)

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
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021

Information for Patients

Pneumocystis Infections

Pneumocystis jirovecii is a tiny fungus that lives in the lungs of many people. Most people's immune systems keep the fungus under control. But if you have a weakened immune system, the fungus can make you very sick.

The most common type of infection is pneumocystis pneumonia (PCP). PCP once was the major cause of death for people with HIV/AIDS. But now, it is possible to prevent or treat most cases. The key to surviving PCP is early treatment. The first signs of PCP are fever, dry cough, shortness of breath, and fatigue. If you have a weakened immune system and have these symptoms, see your doctor right away.

To diagnose PCP, doctors use a microscope to look for the fungus in a sample of lung fluid or tissue. Treatment is with antibiotics.

There is no vaccine to prevent PCP. Some people who are at high risk of getting PCP may need to take antibiotics to prevent it.

  • Pneumocystis jiroveci pneumonia (Medical Encyclopedia)

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