2025 ICD-10-CM Diagnosis Code B59

Pneumocystosis

ICD-10-CM Code:
B59
ICD-10 Code for:
Pneumocystosis
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Not chronic
Code Navigator:

B59 is a billable diagnosis code used to specify a medical diagnosis of pneumocystosis. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2024 through September 30, 2025.

Code Classification

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

Approximate Synonyms

The following list of clinical terms are approximate synonyms, alternative descriptions, or common phrases that might be used by patients, healthcare providers, or medical coders to describe the same condition. These synonyms and related diagnosis terms are often used when searching for an ICD-10 code, especially when the exact medical terminology is unclear. Whether you're looking for lay terms, similar diagnosis names, or common language alternatives, this list can help guide you to the correct ICD-10 classification.

  • Colonization of respiratory tract with Pneumocystis jirovecii
  • Disseminated pneumocystosis
  • Extrapulmonary pneumocystis infection
  • Fungal choroiditis
  • Infection by Pneumocystis jirovecii
  • Infection by Pneumocystis jirovecii
  • Infection by Pneumocystis jirovecii
  • Infection caused by Pneumocystis co-occurrent with human immunodeficiency virus infection
  • Infection caused by Pneumocystis co-occurrent with human immunodeficiency virus infection
  • Infection of lung caused by Pneumocystis
  • Infection of lung caused by Pneumocystis
  • Infection of lung caused by Pneumocystis
  • Inflammation of choroid caused by Pneumocystis jirovecii
  • Lung cyst
  • Pneumocystis jirovecii lung cyst
  • Pneumocystis jirovecii present
  • Pneumocystosis
  • Pneumocystosis
  • Pneumocystosis
  • Pneumocystosis
  • Pneumocystosis
  • Pneumocystosis
  • Pneumocystosis pneumonia
  • Pneumocystosis with AIDS
  • Pulmonary nodule caused by Pneumocystis
  • Spontaneous pneumothorax
  • Spontaneous pneumothorax due to infection caused by Pneumocystis jirovecii

Clinical Classification

Clinical Classifications group individual ICD-10-CM diagnosis codes into broader, clinically meaningful categories. These categories help simplify complex data by organizing related conditions under common clinical themes.

They are especially useful for data analysis, reporting, and clinical decision-making. Even when diagnosis codes differ, similar conditions can be grouped together based on their clinical relevance. Each category is assigned a unique CCSR code that represents a specific clinical concept, often tied to a body system or medical specialty.

Fungal infections

CCSR Code: INF004

Inpatient Default: N - Not default inpatient assignment for principal diagnosis or first-listed diagnosis.

Outpatient Default: N - Not default outpatient assignment for principal diagnosis or first-listed diagnosis.

Pneumonia (except that caused by tuberculosis)

CCSR Code: RSP002

Inpatient Default: Y - Yes, default inpatient assignment for principal diagnosis or first-listed diagnosis.

Outpatient Default: Y - Yes, default outpatient assignment for principal diagnosis or first-listed diagnosis.

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.


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 References

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

Convert B59 to ICD-9-CM

Below are the ICD-9 codes that most closely match this ICD-10 code, based on the General Equivalence Mappings (GEMs). This ICD-10 to ICD-9 crosswalk tool is helpful for coders who need to reference legacy diagnosis codes for audits, historical claims, or approximate code comparisons.

Pneumocystosis

ICD-9-CM: 136.3

This is a direct match with no additional mapping qualifiers. The absence of a flag generally means the mapping is considered exact or precise. In other words, the ICD-10 code maps cleanly to the ICD-9 code without qualification, approximation, or needing multiple codes.

Patient Education


Pneumocystis Infections

What is Pneumocystis jirovecii?

Pneumocystis jirovecii is a fungus that is common throughout the world. Many people have been exposed to it as children. Some people have the fungus in their lungs. If you are healthy, it usually will not make you sick. But it can make you sick if you have a weakened immune system, for example if you:

  • Have HIV
  • Have an autoimmune disease
  • Have cancer
  • Have a chronic (long-lasting) lung disease
  • Had an organ or bone marrow transplant
  • Take medicines which weaken your immune system, such as chemotherapy and steroids

How does Pneumocystis jirovecii spread?

Pneumocystis jirovecii can spread from person to person through the air. You can spread it to others even if it isn't making you sick.

What is pneumocystis pneumonia (PCP)?

The most common type of infection that Pneumocystis jirovecii causes is pneumocystis pneumonia (PCP). Pneumonia is an infection in one or both of the lungs. It causes the air sacs of the lungs to fill up with fluid or pus.

What are the symptoms of pneumocystis pneumonia (PCP)?

The symptoms of PCP can develop over several days or weeks. They may include:

  • Fever
  • Cough
  • Trouble breathing
  • Chest pain
  • Chills
  • Fatigue

Contact your healthcare provider if you have symptoms that you think are related to PCP. Since PCP can be life-threatening, it's important to get early treatment.

How is pneumocystis pneumonia (PCP) diagnosed?

To find out if you have PCP, your provider will take a sample of fluid or tissue from your lungs. You may cough up the sample (called sputum), have fluid collected during a bronchoalveolar lavage, or have tissue taken with a biopsy. They will send the sample to the lab to check for Pneumocystis.

What are the treatments for pneumocystis pneumonia (PCP)?

The treatment for PCP is with antibiotics, either by mouth or intravenously (by IV). You need to take them for about 3 weeks. If you have a severe case of PCP, you might need treatment in the hospital.

Can pneumocystis pneumonia (PCP) be prevented?

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.

Centers for Disease Control and Prevention


[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.