ICD-10 C26.1
Billable / Specific HCC v28: 11Malignant neoplasm of spleen
About ICD-10-CM C26.1
ICD-10-CM code C26.1 represents Malignant neoplasm of spleen. This is a billable/specific code in the Neoplasms chapter (block C26). The 2026 edition of ICD-10-CM C26.1 became effective on October 1, 2025.
Coding Tips for C26.1
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
C26.1 is a CMS-HCC v28 risk-adjustment code (category 11). To count for the patient Risk Adjustment Factor (RAF), document the diagnosis with MEAT language each calendar year: Monitored, Evaluated, Assessed, Treated. A diagnosis on the problem list alone does not satisfy CMS RADV audit standards. Include the diagnosis in the assessment with current status and current treatment plan.
Type 1 Excludes
Pure excludes, these codes can never be coded together with C26.1. The conditions are mutually exclusive (e.g., congenital vs acquired forms).
- Hodgkin lymphoma (C81.-)
- non-Hodgkin lymphoma (C82-C85)
Medicare Advantage HCC Impact
Capture this diagnosis annually for accurate risk adjustment. Missed HCC captures are the #1 revenue leak in Medicare Advantage risk programs.
Medicare LCD Coverage for C26.1
Local Coverage Determinations (LCDs) from CMS MACs that list C26.1 as a covered diagnosis.
Showing top 10 of 687 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing C26.1.
1 Cigna
5 Medicare
CPT Codes Commonly Billed with C26.1
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 C26.1 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 |
|---|---|---|
| C26.1 | 1591 | 00000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To C26.1
Other codes in section C15-C26 (Malignant neoplasms of digestive organs).
ICD-10 C26.1, Billing FAQ
Is ICD-10 code C26.1 billable? +
Yes, C26.1 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
What codes are Type 1 Excludes for C26.1? +
Type 1 Excludes (never code together with C26.1): Hodgkin lymphoma (C81.-); non-Hodgkin lymphoma (C82-C85)
Does C26.1 affect Medicare Advantage HCC risk adjustment? +
Yes. C26.1 maps to CMS-HCC v28 category 11. Capture this diagnosis annually for accurate Medicare Advantage risk score.
What ICD-9 codes does C26.1 map to? +
Per CMS GEMs, C26.1 maps to ICD-9 codes: 1591. Useful for legacy data review and historical claim analysis.
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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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