ICD-10 Logo
ICDxICD-10 Medical Coding
ICD-10 Logo
ICDxICD-10 Medical Coding
ICD 10 CodesDiagnoses
ICD 10 CodesDiagnoses
ICD-10 Logo
ICDxICD-10 Medical Coding

Comprehensive ICD-10-CM code reference with AI-powered search capabilities.

© 2025 ICD Code Compass. All rights reserved.

Browse

  • All Chapters
  • All Categories
  • Diagnoses

Tools

  • AI Code Search
ICD-10-CM codes are maintained by the CDC and CMS. This tool is for reference purposes only.
v1.0.0
ICD-10 Guide
ICD-10 CodesB49

B49

Unspecified mycosis

BILLABLE STATUSYes
IMPLEMENTATION DATEOctober 1, 2015
LAST UPDATED09/05/2025

Code Description

ICD-10 B49 is a billable code used to indicate a diagnosis of unspecified mycosis.

Key Diagnostic Point:

Unspecified mycosis refers to a fungal infection that does not fit into a more specific category of mycosis. Fungal infections can range from superficial skin infections to systemic infections that affect multiple organ systems. The term 'mycosis' encompasses a variety of fungal diseases caused by different fungi, including dermatophytes, yeasts, and molds. Patients with unspecified mycosis may present with symptoms such as skin lesions, respiratory distress, or systemic symptoms depending on the site of infection. The diagnosis often requires a thorough clinical evaluation, including patient history, physical examination, and laboratory tests such as cultures or serological tests. Treatment typically involves antifungal medications, which can vary based on the type of fungus and the severity of the infection. Immunocompromised patients, such as those with HIV/AIDS, cancer, or those on immunosuppressive therapy, are at a higher risk for developing severe fungal infections, making accurate diagnosis and treatment critical. Due to the broad nature of this code, it is essential for coders to ensure that the documentation supports the diagnosis of unspecified mycosis and to consider the patient's overall clinical picture.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Lack of specificity in the diagnosis
  • Variety of potential underlying causes
  • Need for comprehensive documentation to support the diagnosis
  • Potential overlap with other fungal infection codes

Audit Risk Factors

  • Insufficient documentation to support the unspecified diagnosis
  • Inconsistent coding with clinical findings
  • Failure to document immunocompromised status
  • Lack of follow-up or treatment documentation

Specialty Focus

Medical Specialties

Infectious Disease

Documentation Requirements

Detailed patient history, laboratory results, and treatment plans must be documented.

Common Clinical Scenarios

Patients presenting with systemic symptoms and suspected fungal infections.

Billing Considerations

Consideration of the patient's immunocompromised status and previous fungal infections.

Dermatology

Documentation Requirements

Photographic evidence of skin lesions and detailed descriptions of symptoms.

Common Clinical Scenarios

Patients with skin lesions suspected to be fungal in nature.

Billing Considerations

Differentiating between fungal infections and other dermatological conditions.

Coding Guidelines

Inclusion Criteria

Use B49 When
  • According to ICD
  • 10 guidelines, B49 should be used when a fungal infection is diagnosed but does not fit into a more specific category
  • Coders should ensure that the documentation supports the diagnosis and that other potential fungal infections have been ruled out

Exclusion Criteria

Do NOT use B49 When
No specific exclusions found.

Related CPT Codes

87102CPT Code

Culture, fungal

Clinical Scenario

Used when a fungal infection is suspected and cultures are taken.

Documentation Requirements

Document the reason for the culture and any relevant clinical findings.

Specialty Considerations

Infectious disease specialists may require additional details on the patient's history.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of fungal infections, but B49 remains a catch-all for unspecified cases. Coders must be diligent in ensuring that the documentation supports the use of this code to avoid denials and audits.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more specific coding of fungal infections, but B49 remains a catch-all for unspecified cases. Coders must be diligent in ensuring that the documentation supports the use of this code to avoid denials and audits.

Reimbursement & Billing Impact

The transition to ICD-10 has allowed for more specific coding of fungal infections, but B49 remains a catch-all for unspecified cases. Coders must be diligent in ensuring that the documentation supports the use of this code to avoid denials and audits.

Resources

Clinical References

  • •
    CDC Fungal Diseases

Coding & Billing References

  • •
    CDC Fungal Diseases

Frequently Asked Questions

When should I use code B49?

Use code B49 when a fungal infection is suspected but not specifically identified. Ensure that documentation supports the diagnosis and that other fungal infections have been ruled out.