ICD-10 C4A.11
Non-Billable HeaderMerkel cell carcinoma of right eyelid, including canthus
About ICD-10-CM C4A.11
ICD-10-CM code C4A.11 represents Merkel cell carcinoma of right eyelid, including canthus. This is a non-billable header code in the Neoplasms chapter (block C4A). The 2026 edition of ICD-10-CM C4A.11 became effective on October 1, 2025. Non-billable codes cannot be used as a primary or secondary diagnosis on a claim, use a more specific child code instead.
Medicare LCD Coverage for C4A.11
Local Coverage Determinations (LCDs) from CMS MACs that list C4A.11 as a covered diagnosis.
This doesn't mean the code isn't covered, it means no MAC has issued a Local Coverage Determination naming this specific code. Coverage may still apply under National Coverage Determinations or general medical-necessity rules.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing C4A.11.
Our payer policy database covers Aetna, Cigna, Anthem, BCBS, Humana, and Medicare Advantage plans, but C4A.11 doesn't currently appear in any indexed policy. The code may still be covered under standard plan benefits.
CPT Codes Commonly Billed with C4A.11
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
We don't have CPT pairings indexed for this specific code yet. Use the CPT search above to find common procedures, or check your payer's published medical policy for code-specific guidance.
Convert C4A.11 to ICD-9-CM
Per CMS General Equivalence Mappings (GEMs), useful for legacy data review and historical claim analysis.
| ICD-10 | ICD-9 | Mapping Flags |
|---|---|---|
| C4A.11 | 20931 | 10000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To C4A.11
Other codes in section C43-C44 (Melanoma and other malignant neoplasms of skin).
ICD-10 C4A.11, Billing FAQ
Is ICD-10 code C4A.11 billable? +
No, C4A.11 is a non-billable header code. Use a more specific child code from block C4A when submitting claims.
What ICD-9 codes does C4A.11 map to? +
Per CMS GEMs, C4A.11 maps to ICD-9 codes: 20931. Useful for legacy data review and historical claim analysis.
Get the full PayerReady toolkit
Free access to CPT/ICD-10 lookup, denial appeals, fee comparator, and claim auditing with credentialing enrollment.
Start free →Run this code through our claim audit tool
Check NCCI bundling, MUE limits, and modifier logic before submission.
Try the auditor →Did this page help?
Quick signal so we know what to improve.
If you want a code reference page that doesn't exist yet, email coding@payerready.com.
Tell us what's missing or wrong: coding@payerready.com. We respond within 5 business days.
Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on June 1, 2026.
Powered by 11K CPT · 98K ICD-10 · 860K MPFS rates · 4.5M NCCI edits · 9.5M NPIs. Our data methodology · About our coding team