1. Home
  2. ICD-10-CM Codes
  3. A00–B99
  4. A30-A49
  5. A42
  6. 2024 ICD-10-CM Code A42
Version 2024
Non-Billable Code

2024 ICD-10-CM Diagnosis Code A42

Actinomycosis

ICD-10-CM Code:
A42
ICD-10 Code for:
Actinomycosis
Is Billable?
Not Valid for Submission
Code Navigator:

Code Classification

  • Certain infectious and parasitic diseases
    (A00–B99)
    • Other bacterial diseases
      (A30-A49)
      • Actinomycosis
        (A42)

A42 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of actinomycosis. The code is not specific and is NOT valid for the year 2024 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

Specific Coding Applicable to Actinomycosis

Non-specific codes like A42 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10-CM codes with a higher level of specificity when coding for actinomycosis:

  • Use A42.0 for Pulmonary actinomycosis - BILLABLE CODE

  • Use A42.1 for Abdominal actinomycosis - BILLABLE CODE

  • Use A42.2 for Cervicofacial actinomycosis - BILLABLE CODE

  • Use A42.7 for Actinomycotic sepsis - BILLABLE CODE

  • A42.8 for Other forms of actinomycosis - NON-BILLABLE CODE

  • Use A42.81 for Actinomycotic meningitis - BILLABLE CODE

  • Use A42.82 for Actinomycotic encephalitis - BILLABLE CODE

  • Use A42.89 for Other forms of actinomycosis - BILLABLE CODE

  • Use A42.9 for Actinomycosis, unspecified - BILLABLE CODE

Clinical Information

  • Actinomycosis

    infections with bacteria of the genus actinomyces.

  • Actinomycosis, Cervicofacial

    a form of actinomycosis characterized by slow-growing inflammatory lesions of the lymph nodes that drain the mouth (lumpy jaw), reddening of the overlying skin, and intraperitoneal abscesses.

  • Actinomyces

    a genus of gram-positive, rod-shaped bacteria whose organisms are nonmotile. filaments that may be present in certain species are either straight or wavy and may have swollen or clubbed heads.

  • Actinomycosis

    an infectious process caused by bacteria of the actinomyces species. it is characterized by the formation of purulent and painful abscesses in the mouth, lungs and gastrointestinal tract.

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.


Type 1 Excludes

Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.

Patient Education


Bacterial Infections

Bacteria are living things that have only one cell. Under a microscope, they look like balls, rods, or spirals. They are so small that a line of 1,000 could fit across a pencil eraser. Most types of don't make you sick. Many types are helpful. Some of them help to digest food, destroy disease-causing cells, and give the body needed vitamins. Bacteria are also used in making healthy foods like yogurt and cheese.

But infectious bacteria can make you ill. They reproduce quickly in your body. Many give off chemicals called toxins, which can damage tissue and make you sick. Examples of bacteria that cause infections include Streptococcus, Staphylococcus, and E. coli.

Antibiotics are the usual treatment. When you take antibiotics, follow the directions carefully. Each time you take antibiotics, you increase the chances that bacteria in your body will learn to resist them causing antibiotic resistance. Later, you could get or spread an infection that those antibiotics cannot cure.

NIH: National Institute of Allergy and Infectious Diseases


[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.