| ICD-10 Code | Description |
| C4A.0 | Merkel cell carcinoma of lip |
| C4A.10 | Merkel cell carcinoma of unspecified eyelid, including canthus |
| C4A.111 | Merkel cell carcinoma of right upper eyelid, including canthus |
| C4A.112 | Merkel cell carcinoma of right lower eyelid, including canthus |
| C4A.121 | Merkel cell carcinoma of left upper eyelid, including canthus |
| C4A.122 | Merkel cell carcinoma of left lower eyelid, including canthus |
| C4A.20 | Merkel cell carcinoma of unspecified ear and external auricular canal |
| C4A.21 | Merkel cell carcinoma of right ear and external auricular canal |
| C4A.22 | Merkel cell carcinoma of left ear and external auricular canal |
| C4A.30 | Merkel cell carcinoma of unspecified part of face |
| C4A.31 | Merkel cell carcinoma of nose |
| C4A.39 | Merkel cell carcinoma of other parts of face |
| C4A.4 | Merkel cell carcinoma of scalp and neck |
| C4A.51 | Merkel cell carcinoma of anal skin |
| C4A.52 | Merkel cell carcinoma of skin of breast |
| C4A.59 | Merkel cell carcinoma of other part of trunk |
| C4A.60 | Merkel cell carcinoma of unspecified upper limb, including shoulder |
| C4A.61 | Merkel cell carcinoma of right upper limb, including shoulder |
| C4A.62 | Merkel cell carcinoma of left upper limb, including shoulder |
| C4A.70 | Merkel cell carcinoma of unspecified lower limb, including hip |
| C4A.71 | Merkel cell carcinoma of right lower limb, including hip |
| C4A.72 | Merkel cell carcinoma of left lower limb, including hip |
| C4A.8 | Merkel cell carcinoma of overlapping sites |
| C4A.9 | Merkel cell carcinoma, unspecified |
