ICD-10-CM 2027 diagnosis code
C43.122Malignant melanoma of left lower eyelid, including canthus
C43.122 is a valid, billable ICD-10-CM code for malignant melanoma of left lower 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 C43.122
C43.122 is the ICD-10-CM diagnosis code for malignant melanoma of left lower eyelid, including canthus. It belongs to category C43 (malignant melanoma of skin), block C43-C44 (melanoma and other malignant neoplasms of skin) 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 C43.12 (malignant melanoma of left eyelid, including canthus), C43.122 is specifically for malignant melanoma of left lower eyelid, including canthus. Related codes cover upper eyelid, including canthus (C43.121).
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 C43.122.
Broader instructions also apply from 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.
MDC 02 · Diseases and Disorders of the Eye
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2019 (effective 10/1/2018): Added
- No changes since FY2019.
Common questions about C43.122
Is C43.122 billable?
- Yes. C43.122 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can C43.122 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict C43.122 as a principal diagnosis.
Is C43.122 a CC or MCC?
- No. C43.122 is neither a CC nor an MCC under MS-DRG v44.0.
What DRG does C43.122 group to?
- C43.122 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.