ICD-10 A04.3
Billable / Specific CCEnterohemorrhagic Escherichia coli infection
About ICD-10-CM A04.3
ICD-10-CM code A04.3 represents Enterohemorrhagic Escherichia coli infection. This is a billable/specific code in the Infectious and Parasitic Diseases chapter (block A04). The 2026 edition of ICD-10-CM A04.3 became effective on October 1, 2025.
Coding Tips for A04.3
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
A04.3 is designated CC for MS-DRG grouping. On inpatient claims, this code can shift the DRG to the with-CC variant when documented as a present-on-admission secondary diagnosis. Hospital CDI programs flag CC opportunities during chart review. Failure to capture this code may leave 30 to 80 percent of the inpatient stay revenue unrealized.
Inpatient DRG Impact, CC
codes Enterohemorrhagic Escherichia coli infection. As a Complication/Comorbidity (CC), this contributes to DRG severity adjustment when documented alongside the principal diagnosis.
Medicare LCD Coverage for A04.3
Local Coverage Determinations (LCDs) from CMS MACs that list A04.3 as a covered diagnosis.
Showing top 10 of 696 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing A04.3.
5 Medicare
CPT Codes Commonly Billed with A04.3
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 45341 CMS LCD: Billing and Coding: Colonoscopy and Sigmoidoscopy-Diagnostic CMS LCD
- 45331 CMS LCD: Billing and Coding: Colonoscopy and Sigmoidoscopy-Diagnostic CMS LCD
- 45337 CMS LCD: Billing and Coding: Colonoscopy and Sigmoidoscopy-Diagnostic CMS LCD
- 45332 CMS LCD: Billing and Coding: Colonoscopy and Sigmoidoscopy-Diagnostic CMS LCD
- 45334 CMS LCD: Billing and Coding: Colonoscopy and Sigmoidoscopy-Diagnostic CMS LCD
- 45335 CMS LCD: Billing and Coding: Colonoscopy and Sigmoidoscopy-Diagnostic CMS LCD
- 45342 CMS LCD: Billing and Coding: Colonoscopy and Sigmoidoscopy-Diagnostic CMS LCD
- 45330 CMS LCD: Billing and Coding: Colonoscopy and Sigmoidoscopy-Diagnostic CMS LCD
- 45338 CMS LCD: Billing and Coding: Colonoscopy and Sigmoidoscopy-Diagnostic CMS LCD
- 45333 CMS LCD: Billing and Coding: Colonoscopy and Sigmoidoscopy-Diagnostic CMS LCD
Convert A04.3 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 |
|---|---|---|
| A04.3 | 00804 | 00000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To A04.3
Other codes in section A00-A09 (Intestinal infectious diseases).
ICD-10 A04.3, Billing FAQ
Is ICD-10 code A04.3 billable? +
Yes, A04.3 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
Is A04.3 a CC or MCC for inpatient DRG? +
Yes, this code is designated as CC. Documenting as a secondary diagnosis on inpatient claims can shift the DRG to a higher-weighted category.
What CPT codes are commonly billed with A04.3? +
Procedures frequently paired with A04.3 include: 45341, 45331, 45337, 45332, 45334.
What ICD-9 codes does A04.3 map to? +
Per CMS GEMs, A04.3 maps to ICD-9 codes: 00804. 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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