2026 ICD-10-CM Diagnosis Code D03.51Melanoma in situ of anal skin

ICD-10-CM Codes›C00–D49›D00-D09›D03

ICD-10-CM D03.51
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

D03.51 is a billable ICD-10-CM diagnosis code for melanoma in situ of anal skin. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Skin cancers - melanoma.

Code Identity

ICD-10-CM Code
D03.51
Billable Status
Yes — Valid for Submission
Code Describes
Melanoma in situ of anal skin
Short Description
Melanoma in situ of anal skin
Same as the full description in the CMS dataset.
Parent Code
D03.5
Melanoma in situ of trunk

Code Classification

ChapterC00–D49Neoplasms
SectionD00-D09In situ neoplasms
CategoryD03Melanoma in situ
This CodeD03.51Melanoma in situ of anal skin

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Melanoma in situ of anal skin
  • Melanoma in situ of perianal skin
  • Melanoma in situ of trunk

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Melanoma in situ of anal margin
  • Melanoma in situ of perianal skin

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Melanoma(malignant)
      • in situ
        • anus, anal (margin) (skin)
    • Melanoma(malignant)
      • in situ
        • perianal skin
    • Melanoma(malignant)
      • in situ
        • perineum

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NEO025
Skin cancers - melanoma
Default principal diagnosis: inpatient Yes · outpatient Yes

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."

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert D03.51 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
172.5 Malig melanoma trunk
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About D03.51Overview

Is D03.51 (Melanoma in situ of trunk) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report melanoma in situ of anal skin on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does D03.51 group to?

When melanoma in situ of anal skin 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 D03.51?

Under the General Equivalence Mappings, melanoma in situ of anal skin converts to ICD-9-CM 172.5 (malig melanoma trunk). 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.