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ICD-10-CM 2027 diagnosis code

D03.121Melanoma in situ of left upper eyelid, including canthus

✓ Billable / specific

D03.121 is a valid, billable ICD-10-CM code for melanoma in situ of left upper eyelid, including canthus. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Code last changed in FY2019 (effective October 1, 2018). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About D03.121

D03.121 is the ICD-10-CM diagnosis code for melanoma in situ of left upper eyelid, including canthus. It belongs to category D03 (melanoma in situ), block D00-D09 (in situ neoplasms) and chapter 2 (neoplasms). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within D03.12 (melanoma in situ of left eyelid, including canthus), D03.121 is specifically for melanoma in situ of left upper eyelid, including canthus. Related codes cover lower eyelid, including canthus (D03.122).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 124 (Other Disorders of the Eye with MCC or Thrombolytic Agent, relative weight 1.2471) and DRG 125 (Other Disorders of the Eye without MCC, relative weight 0.7702), in MDC 02 (Diseases and Disorders of the Eye), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It was added in FY2019, effective October 1, 2018.

Notes that apply from higher levels

Instructions written at a parent level also apply to D03.121.

Broader instructions also apply from D00-D09 In situ neoplasms and Chapter 2: Neoplasms.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2019 (effective 10/1/2018): Added
  • No changes since FY2019.

Common questions about D03.121

Is D03.121 billable?

Yes. D03.121 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can D03.121 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict D03.121 as a principal diagnosis.

Is D03.121 a CC or MCC?

No. D03.121 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does D03.121 group to?

D03.121 is used in the MS-DRG v44.0 logic for MS-DRG 124 (Other Disorders of the Eye with MCC or Thrombolytic Agent) and MS-DRG 125 (Other Disorders of the Eye without MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.