A42
Non-Billable

Actinomycosis

Non-Billable / Non-Specific Code

What is Actinomycosis?

ICD-10-CM A42 is the diagnosis code for Actinomycosis. This code falls under the section "Other bacterial diseases" within Chapter 1 — Certain infectious and parasitic diseases (A00-B99). It is a non-billable/non-specific ICD-10-CM code that should not be used for reimbursement. A more specific sub-code is required for billing. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.

⛔ Excludes1

Coding Guidelines for A42

⛔ Type 1 Excludes (Never code together)

The following conditions should never be coded at the same time as A42. They are mutually exclusive:

  • actinomycetoma (B47.1)

ICD-10-CM Code Hierarchy

Understanding where A42 sits in the ICD-10-CM classification helps ensure proper coding:

Sub-Codes 6 entries
A42.0Pulmonary actinomycosisBillableA42.1Abdominal actinomycosisBillableA42.2Cervicofacial actinomycosisBillableA42.7Actinomycotic sepsisBillableA42.8Other forms of actinomycosisNon-BillableA42.81Actinomycotic meningitisBillableA42.82Actinomycotic encephalitisBillableA42.89Other forms of actinomycosisBillableA42.9Actinomycosis, unspecifiedBillable
Related Codes

Frequently Asked Questions

Is A42 a billable ICD-10-CM code?

No, A42 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.

What does A42 mean?

A42 is the ICD-10-CM diagnosis code for "Actinomycosis". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.

What section is A42 in?

A42 is located in Section A30-A49 — "Other bacterial diseases" within Chapter 1 of the ICD-10-CM Tabular List.

What are the sub-codes of A42?

A42 has 6 sub-code(s) that provide more specific detail: A42.0, A42.1, A42.2, A42.7, A42.8 and more.

When should I use A42?

Use A42 when the patients documented diagnosis matches "Actinomycosis" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.

People Also Ask

What is the ICD-10 code for Actinomycosis?

The ICD-10-CM code for Actinomycosis is A42.

Can A42 be used for primary diagnosis?

No, A42 is non-billable. Use a more specific sub-code for primary diagnosis billing.

What chapter is A42 in?

A42 is in Chapter 1 of the ICD-10-CM Tabular List.

What conditions are excluded from A42?

Type 1 Excludes for A42 include: actinomycetoma (B47.1).

Is A42 valid for 2026?

Yes, A42 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.

See Also

← PreviousA41.9Sepsis, unspecified organismNext →A42.0Pulmonary actinomycosis
Code Details
A42
Actinomycosis
Non-Billable / Non-Specific Code
1 — Certain infectious and parasitic diseases (A00-B99)
A30-A49 — Other bacterial diseases
2026 ICD-10-CM