ICD-10 C79
Non-Billable HeaderSecondary malignant neoplasm of other and unspecified sites
About ICD-10-CM C79
ICD-10-CM code C79 represents Secondary malignant neoplasm of other and unspecified sites. This is a non-billable header code in the chapter (block C79). The 2026 edition of ICD-10-CM C79 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.
Type 1 Excludes
Pure excludes, these codes can never be coded together with C79. The conditions are mutually exclusive (e.g., congenital vs acquired forms).
- secondary carcinoid tumors (C7B.-)
- secondary neuroendocrine tumors (C7B.-)
Medicare LCD Coverage for C79
Local Coverage Determinations (LCDs) from CMS MACs that list C79 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 C79.
Our payer policy database covers Aetna, Cigna, Anthem, BCBS, Humana, and Medicare Advantage plans, but C79 doesn't currently appear in any indexed policy. The code may still be covered under standard plan benefits.
CPT Codes Commonly Billed with C79
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.
Codes Adjacent To C79
Other codes in section C76-C80 (Malignant neoplasms of ill-defined, other secondary and unspecified sites).
ICD-10 C79, Billing FAQ
Is ICD-10 code C79 billable? +
No, C79 is a non-billable header code. Use a more specific child code from block C79 when submitting claims.
What codes are Type 1 Excludes for C79? +
Type 1 Excludes (never code together with C79): secondary carcinoid tumors (C7B.-); secondary neuroendocrine tumors (C7B.-)
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 May 31, 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