C4A.121 — Merkel cell carcinoma of left upper eyelid, including canthus
Billable
Is C4A.121 billable?
Yes — C4A.121 is billable for FY2027. C4A.121 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. C4A.121 may be submitted for encounters from October 1, 2026 through September 30, 2027.
C4A.121 at a glance
| Code | C4A.121 |
|---|---|
| Description | Merkel cell carcinoma of left upper eyelid, including canthus |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does C4A.121 group to?
C4A.121 sits in MDC 09 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 595Major Skin Disorders with MCCmedical
- 596Major Skin Disorders without MCCmedical
How is C4A.121 listed in the Alphabetic Index?
The Alphabetic Index lists these routes under C4A.1, the nearest indexed parent of C4A.121. Use them to find the family, then select the specific code.
- Carcinoma › Merkel cell › canthus (malignant)
- Carcinoma › Merkel cell › eyelid, including canthus (malignant)
How long has C4A.121 existed?
C4A.121 first appears in FY2019.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.