2026 ICD-10-CM Diagnosis Code C43.21Malignant melanoma of right ear and external auricular canal
ICD-10-CM Codes›C00–D49›C43-C44›C43
- Billable — Valid for Submission
- Chronic Condition
C43.21 is a billable ICD-10-CM diagnosis code for malignant melanoma of right ear and external auricular canal. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 595 through 596. Coders also document this condition as malignant melanoma of skin of ear. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Skin cancers - melanoma.
Code Identity
Code Classification
Quality Payment Program MeasuresBilling
Medicare quality measures that can apply when C43.21 is part of the patient record.
Melanoma Reporting
High Priority: YES
Measure Type: Process
Submission Methods: Claims, Registry
Description: Pathology reports for primary malignant cutaneous melanoma that include the pT category, thickness, ulceration and mitotic rate, peripheral and deep margin status and presence or absence of microsatellitosis for invasive tumors.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Malignant melanoma of skin of ear
- Malignant melanoma of skin of right ear
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Melanoma
Melanoma is the most serious type of skin cancer. Often the first sign of melanoma is a change in the size, shape, color, or feel of a mole. Most melanomas have a black or black-blue area. Melanoma may also appear as a new mole. It may be black, abnormal, or "ugly looking."
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Convert C43.21 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About C43.21Overview
Is C43.21 (Malignant melanoma of ear and external auricular canal) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report malignant melanoma of right ear and external auricular canal on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does C43.21 group to?
When malignant melanoma of right ear and external auricular canal is the principal diagnosis on an inpatient stay, it groups to MS-DRG 595, 596, with relative weights from 1.0825 to 2.1207 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of C43.21?
Under the General Equivalence Mappings, malignant melanoma of right ear and external auricular canal converts to ICD-9-CM 172.2 (malig melanoma ear). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:
- The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
- The condition places limitations on self-care, independent living, and social interactions.
