ICD-10 Z17.421
Billable / SpecificHormone receptor negative with human epidermal growth factor receptor 2 negative status
About ICD-10-CM Z17.421
ICD-10-CM code Z17.421 represents Hormone receptor negative with human epidermal growth factor receptor 2 negative status. This is a billable/specific code in the Factors Influencing Health Status chapter (block Z17). The 2026 edition of ICD-10-CM Z17.421 became effective on October 1, 2025.
Inclusion Terms / Approximate Synonyms
Clinical terms and conditions classified under Z17.421. Per CMS ICD-10-CM Tabular 2026.
- HR- with HER2-
- TNBC
- Triple negative breast cancer
Medicare LCD Coverage for Z17.421
Local Coverage Determinations (LCDs) from CMS MACs that list Z17.421 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 Z17.421.
Our payer policy database covers Aetna, Cigna, Anthem, BCBS, Humana, and Medicare Advantage plans, but Z17.421 doesn't currently appear in any indexed policy. The code may still be covered under standard plan benefits.
CPT Codes Commonly Billed with Z17.421
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 Z17.421
Other codes in section Z17 (Estrogen, and other hormones and factors receptor status).
ICD-10 Z17.421, Billing FAQ
Is ICD-10 code Z17.421 billable? +
Yes, Z17.421 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
What other names or terms map to Z17.421? +
ICD-10 Z17.421 includes: HR- with HER2-; TNBC; Triple negative breast cancer.
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on May 31, 2026.
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