ICD-10 Guide

A42.89

Other forms of actinomycosis

BILLABLE STATUSYes

IMPLEMENTATION DATEOctober 1, 2015

LAST UPDATED09/05/2025

Code Description

ICD-10 A42.89 is a billable code used to indicate a diagnosis of other forms of actinomycosis.

Key Diagnostic Point:

Actinomycosis is a chronic bacterial infection caused primarily by Actinomyces species, which are anaerobic, gram-positive bacteria. The condition is characterized by the formation of abscesses and the development of sinus tracts that can drain pus. While actinomycosis can affect various body parts, including the cervicofacial region, thorax, abdomen, and pelvis, the term 'other forms of actinomycosis' encompasses atypical presentations that do not fit into the more common categories. This code is particularly relevant in immunocompromised patients, where opportunistic infections can manifest in unusual ways. Diagnostic challenges arise due to the nonspecific symptoms and the need for culture or histological confirmation, which can delay treatment. In immunocompromised individuals, the risk of disseminated disease increases, complicating the clinical picture and necessitating a high index of suspicion for timely diagnosis and management.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

Variability in clinical presentation and localization of infection
Need for specific laboratory confirmation (culture or histology)
Differentiation from other similar infections (e.g., tuberculosis, fungal infections)
Documentation of immunocompromised status and its impact on disease manifestation

Audit Risk Factors

Inadequate documentation of the immunocompromised status
Failure to provide laboratory confirmation of actinomycosis
Misclassification of the site of infection
Lack of detailed clinical history supporting the diagnosis

Specialty Focus

Medical Specialties

Infectious Disease

Documentation Requirements

Detailed clinical notes, laboratory results, and imaging studies.

Common Clinical Scenarios

Patients presenting with chronic abscesses, especially in immunocompromised individuals.

Billing Considerations

Documentation must clearly indicate the site of infection and any underlying conditions.

Pulmonology

Documentation Requirements

Pulmonary function tests, imaging results, and treatment plans.

Common Clinical Scenarios

Patients with respiratory symptoms and a history of immunosuppression.

Billing Considerations

Clear differentiation from other pulmonary infections is crucial.

Coding Guidelines

Inclusion Criteria

Use A42.89 When

According to ICD
10 coding guidelines, A42
89 should be used when the actinomycosis does not fit into the more specific categories
Coders must ensure that the documentation supports the diagnosis and that the condition is not better classified under other codes

Exclusion Criteria

Do NOT use A42.89 When

No specific exclusions found.

Related CPT Codes

87070CPT Code

Culture, bacterial, any source

Clinical Scenario

Used when cultures are taken to confirm actinomycosis.

Documentation Requirements

Document the source of the culture and the clinical rationale.

Specialty Considerations

Infectious disease specialists should ensure that cultures are properly labeled and processed.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of actinomycosis, enabling better tracking of the disease and its manifestations. A42.89 provides a means to capture atypical presentations that may have been overlooked in ICD-9.

ICD-9 vs ICD-10

Reimbursement & Billing Impact

Resources

Clinical References

•
CDC Actinomycosis Information

Coding & Billing References

•
CDC Actinomycosis Information

Frequently Asked Questions

What are the common symptoms of actinomycosis?

Common symptoms include chronic abscess formation, pain at the site of infection, fever, and in some cases, respiratory distress if the lungs are involved.

How is actinomycosis diagnosed?

Diagnosis typically involves clinical evaluation, imaging studies, and microbiological culture or histological examination of tissue samples.

What is the treatment for actinomycosis?

Treatment usually involves prolonged antibiotic therapy, often with penicillin, and may require surgical drainage of abscesses.

ICD-10 A42.89 is a billable code used to indicate a diagnosis of other forms of actinomycosis.