ICD-10 B46.3
Billable / Specific HCC v28: 6 MCCCutaneous mucormycosis
About ICD-10-CM B46.3
ICD-10-CM code B46.3 represents Cutaneous mucormycosis. This is a billable/specific code in the Infectious and Parasitic Diseases chapter (block B46). The 2026 edition of ICD-10-CM B46.3 became effective on October 1, 2025.
Coding Tips for B46.3
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
B46.3 is a CMS-HCC v28 risk-adjustment code (category 6). 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.
B46.3 is designated MCC for MS-DRG grouping. On inpatient claims, this code can shift the DRG to the with-MCC variant when documented as a present-on-admission secondary diagnosis. Hospital CDI programs flag MCC opportunities during chart review. Failure to capture this code may leave 30 to 80 percent of the inpatient stay revenue unrealized.
Inclusion Terms / Approximate Synonyms
Clinical terms and conditions classified under B46.3. Per CMS ICD-10-CM Tabular 2026.
- Subcutaneous mucormycosis
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.
Inpatient DRG Impact, MCC
codes Cutaneous mucormycosis. As a Major Complication/Comorbidity (MCC), this can shift the DRG assignment to a higher-weighted category, substantial reimbursement impact.
Medicare LCD Coverage for B46.3
Local Coverage Determinations (LCDs) from CMS MACs that list B46.3 as a covered diagnosis.
Showing top 2. Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing B46.3.
1 Medicare
CPT Codes Commonly Billed with B46.3
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 B46.3 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 |
|---|---|---|
| B46.3 | 1177 | 10000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To B46.3
Other codes in section B35-B49 (Mycoses).
ICD-10 B46.3, Billing FAQ
Is ICD-10 code B46.3 billable? +
Yes, B46.3 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 B46.3? +
ICD-10 B46.3 includes: Subcutaneous mucormycosis.
Does B46.3 affect Medicare Advantage HCC risk adjustment? +
Yes. B46.3 maps to CMS-HCC v28 category 6. Capture this diagnosis annually for accurate Medicare Advantage risk score.
Is B46.3 a CC or MCC for inpatient DRG? +
Yes, this code is designated as MCC. Documenting as a secondary diagnosis on inpatient claims can shift the DRG to a higher-weighted category.
What ICD-9 codes does B46.3 map to? +
Per CMS GEMs, B46.3 maps to ICD-9 codes: 1177. 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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