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v1.0.0
ICD-10 Guide
ICD-10 CodesC43.9

C43.9

Billable

Malignant melanoma of skin, unspecified

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

Code Description

ICD-10 C43.9 is a billable code used to indicate a diagnosis of malignant melanoma of skin, unspecified.

Key Diagnostic Point:

Malignant melanoma is a serious form of skin cancer that arises from melanocytes, the pigment-producing cells in the skin. The unspecified designation indicates that the specific site of the melanoma is not documented. Melanoma can occur anywhere on the body, and its risk factors include excessive sun exposure, fair skin, and a family history of skin cancer. Staging of melanoma is crucial for determining treatment options and prognosis. The most common staging system is the AJCC (American Joint Committee on Cancer) system, which considers tumor thickness (Breslow thickness), ulceration, and lymph node involvement. Breslow thickness measures the depth of the melanoma in millimeters and is a critical factor in staging; thicker tumors generally indicate a worse prognosis. Sentinel lymph node biopsy (SLNB) is often performed to assess whether cancer has spread to nearby lymph nodes, which is vital for staging and treatment planning. Accurate coding for melanoma is essential for appropriate patient management and reimbursement, as it reflects the severity and complexity of the disease.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Variability in documentation of melanoma type and location
  • Need for precise staging information
  • Interpretation of Breslow thickness measurements
  • Potential for multiple related diagnoses

Audit Risk Factors

  • Inadequate documentation of tumor characteristics
  • Failure to document staging information
  • Misclassification of melanoma type
  • Lack of clarity on treatment plans

Specialty Focus

Medical Specialties

Dermatology

Documentation Requirements

Detailed descriptions of the lesion, including size, location, and characteristics.

Common Clinical Scenarios

Diagnosis and treatment of melanoma, follow-up care, and monitoring for recurrence.

Billing Considerations

Ensure accurate staging and documentation of Breslow thickness for proper coding.

Oncology

Documentation Requirements

Comprehensive treatment plans, including surgical interventions and chemotherapy regimens.

Common Clinical Scenarios

Management of advanced melanoma, including systemic therapies and clinical trials.

Billing Considerations

Documentation must reflect the complexity of treatment and staging to support coding.

Coding Guidelines

Inclusion Criteria

Use C43.9 When
  • Follow the official ICD
  • CM coding guidelines, ensuring that the code is used when the specific site of melanoma is not documented
  • Include additional codes for staging and related conditions as necessary

Exclusion Criteria

Do NOT use C43.9 When
No specific exclusions found.

Related ICD-10 Codes

Related CPT Codes

88305CPT Code

Pathology examination of skin biopsy

Clinical Scenario

Used when a biopsy is performed to confirm melanoma diagnosis.

Documentation Requirements

Pathology report must be included.

Specialty Considerations

Dermatologists and oncologists must ensure accurate reporting of biopsy results.

38500CPT Code

Sentinel lymph node biopsy

Clinical Scenario

Performed to assess lymph node involvement in melanoma staging.

Documentation Requirements

Operative report detailing the procedure and findings.

Specialty Considerations

Oncologists must document the rationale for SLNB.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of melanoma, improving the accuracy of data collection and reimbursement processes. C43.9 serves as a catch-all for unspecified cases, but coders must strive for specificity when possible.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more specific coding of melanoma, improving the accuracy of data collection and reimbursement processes. C43.9 serves as a catch-all for unspecified cases, but coders must strive for specificity when possible.

Reimbursement & Billing Impact

reimbursement processes. C43.9 serves as a catch-all for unspecified cases, but coders must strive for specificity when possible.

Resources

Clinical References

  • •
    American Academy of Dermatology
  • •
    National Cancer Institute

Coding & Billing References

  • •
    American Academy of Dermatology
  • •
    National Cancer Institute

Frequently Asked Questions

When should I use C43.9 instead of a more specific melanoma code?

C43.9 should be used when the specific site of the melanoma is not documented in the medical record. Always strive for the most specific code available.

What documentation is necessary to support the use of C43.9?

Documentation should include the diagnosis of melanoma, any staging information available, and treatment plans. If the site is not specified, this should be clearly noted.