ICD-10 A41.4
Billable / Specific HCC v28: 2 MCCSepsis due to anaerobes
About ICD-10-CM A41.4
ICD-10-CM code A41.4 represents Sepsis due to anaerobes. This is a billable/specific code in the Infectious and Parasitic Diseases chapter (block A41). The 2026 edition of ICD-10-CM A41.4 became effective on October 1, 2025.
Coding Tips for A41.4
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
A41.4 is a CMS-HCC v28 risk-adjustment code (category 2). 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.
A41.4 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.
Type 1 Excludes
Pure excludes, these codes can never be coded together with A41.4. The conditions are mutually exclusive (e.g., congenital vs acquired forms).
- gas gangrene (A48.0)
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 Sepsis due to anaerobes. As a Major Complication/Comorbidity (MCC), this can shift the DRG assignment to a higher-weighted category, substantial reimbursement impact.
Medicare LCD Coverage for A41.4
Local Coverage Determinations (LCDs) from CMS MACs that list A41.4 as a covered diagnosis.
Showing top 10 of 791 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing A41.4.
2 Aetna
5 Medicare
CPT Codes Commonly Billed with A41.4
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 93319 CMS LCD: Billing and Coding: Echocardiography CMS LCD
- 93307 CMS LCD: Billing and Coding: Echocardiography CMS LCD
- 93351 CMS LCD: Billing and Coding: Echocardiography CMS LCD
- 93355 CMS LCD: Billing and Coding: Echocardiography CMS LCD
- J1250 CMS LCD: Billing and Coding: Echocardiography CMS LCD
- 93304 CMS LCD: Billing and Coding: Echocardiography CMS LCD
- 93352 CMS LCD: Billing and Coding: Echocardiography CMS LCD
- J0280 CMS LCD: Billing and Coding: Echocardiography CMS LCD
- 93318 CMS LCD: Billing and Coding: Echocardiography CMS LCD
- 93308 CMS LCD: Billing and Coding: Echocardiography CMS LCD
Convert A41.4 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 |
|---|---|---|
| A41.4 | 0383 | 10111 |
| A41.4 | 99591 | 10112 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To A41.4
Other codes in section A30-A49 (Other bacterial diseases).
ICD-10 A41.4, Billing FAQ
Is ICD-10 code A41.4 billable? +
Yes, A41.4 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 A41.4? +
Type 1 Excludes (never code together with A41.4): gas gangrene (A48.0)
Does A41.4 affect Medicare Advantage HCC risk adjustment? +
Yes. A41.4 maps to CMS-HCC v28 category 2. Capture this diagnosis annually for accurate Medicare Advantage risk score.
Is A41.4 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 CPT codes are commonly billed with A41.4? +
Procedures frequently paired with A41.4 include: 93319, 93307, 93351, 93355, J1250.
What ICD-9 codes does A41.4 map to? +
Per CMS GEMs, A41.4 maps to ICD-9 codes: 0383, 99591. 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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