ICD-10 D89.41
Billable / Specific HCC v28: 47Monoclonal mast cell activation syndrome
About ICD-10-CM D89.41
ICD-10-CM code D89.41 represents Monoclonal mast cell activation syndrome. This is a billable/specific code in the Blood and Blood-forming Organs chapter (block D89). The 2026 edition of ICD-10-CM D89.41 became effective on October 1, 2025.
Coding Tips for D89.41
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
D89.41 is a CMS-HCC v28 risk-adjustment code (category 47). 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.
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 D89.41
Local Coverage Determinations (LCDs) from CMS MACs that list D89.41 as a covered diagnosis.
Showing top 10 of 598 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing D89.41.
5 Medicare
CPT Codes Commonly Billed with D89.41
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 87507 CMS LCD: Billing and Coding: Gastrointestinal Pathogen (GIP) Panels Utilizing Multiplex Nucleic Acid Amplification Techniques (NAATs) CMS LCD
- 87505 CMS LCD: Billing and Coding: Gastrointestinal Pathogen (GIP) Panels Utilizing Multiplex Nucleic Acid Amplification Techniques (NAATs) CMS LCD
- 87506 CMS LCD: Billing and Coding: Gastrointestinal Pathogen (GIP) Panels Utilizing Multiplex Nucleic Acid Amplification Techniques (NAATs) CMS LCD
- 87812 CMS LCD: Billing and Coding: Respiratory Pathogen Panel Testing CMS LCD
- 87428 CMS LCD: Billing and Coding: Respiratory Pathogen Panel Testing CMS LCD
- 87913 CMS LCD: Billing and Coding: Respiratory Pathogen Panel Testing CMS LCD
Convert D89.41 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 |
|---|---|---|
| D89.41 | 2798 | 10000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To D89.41
Other codes in section D80-D89 (Certain disorders involving the immune mechanism).
ICD-10 D89.41, Billing FAQ
Is ICD-10 code D89.41 billable? +
Yes, D89.41 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
Does D89.41 affect Medicare Advantage HCC risk adjustment? +
Yes. D89.41 maps to CMS-HCC v28 category 47. Capture this diagnosis annually for accurate Medicare Advantage risk score.
What CPT codes are commonly billed with D89.41? +
Procedures frequently paired with D89.41 include: 87507, 87505, 87506, 87812, 87428.
What ICD-9 codes does D89.41 map to? +
Per CMS GEMs, D89.41 maps to ICD-9 codes: 2798. 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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