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A03.3 ICD-10-CM Code: Shigellosis due to Shigella sonnei

ICD-10-CM Code View

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FY 2026 Apr update / Certain infectious and parasitic diseases (A00-B99) / Intestinal infectious diseases (A00-A09)

A03.3

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Shigellosis due to Shigella sonnei

This is a bacterial infection of the intestines caused by a specific type of bacteria called Shigella sonnei, which typically causes diarrhea and abdominal cramping. It spreads through contaminated food or water and is contagious from person to person.

CMS-HCC V28

N/A

Not mapped

CMS-HCC V24

N/A

Not mapped

ACA/HHS

N/A

Not mapped

ESRD/PACE

N/A

Not mapped

RXHCC

N/A

Not mapped

Code Book Path

Official
A03Shigellosis
A03.3Shigellosis due to Shigella sonnei

Inclusion Terms

Official
  • Group D shigellosis

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for A03.3 in this effective period.

Related Child Codes

Official
A03.0Shigellosis due to Shigella dysenteriae
A03.1Shigellosis due to Shigella flexneri
A03.2Shigellosis due to Shigella boydii
A03.8Other shigellosis
A03.9Shigellosis, unspecified

Includes

Official

ICD-10-CM does not list Includes notes for A03.3 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for A03.3 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for A03.3 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for A03.3 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for A03.3 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance
Verify the specific Shigella species is documented as sonnei in the medical record; other Shigella species have different codes (A03.0, A03.1, A03.2)
This code includes the causative organism, so do not separately code for the organism; document severity and any complications (dehydration, sepsis) with additional codes if present

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is A03.3 an HCC code?

No. A03.3 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.

Code
A03.3
Description
Shigellosis due to Shigella sonnei
HCC (V28)
No CMS-HCC V28 mapping
RAF
Billable
Yes
Payment year
2026

Coder workflow notes

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This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).

What This Code Means

A03.3 is the ICD-10-CM diagnosis code for shigellosis due to shigella sonnei. This is a bacterial infection of the intestines caused by a specific type of bacteria called Shigella sonnei, which typically causes diarrhea and abdominal cramping. It spreads through contaminated food or water and is contagious from person to person. A03.3 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering intestinal infectious diseases (a00-a09).

A03.3 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

Verify the specific Shigella species is documented as sonnei in the medical record; other Shigella species have different codes (A03.0, A03.1, A03.2).

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for A03.3 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

  • Verify the specific Shigella species is documented as sonnei in the medical record; other Shigella species have different codes (A03.0, A03.1, A03.2)
  • This code includes the causative organism, so do not separately code for the organism; document severity and any complications (dehydration, sepsis) with additional codes if present

Child Codes

Code Hierarchy

A03ShigellosisA03.3Shigellosis due to Shigella sonnei
A03.3Shigellosis due to Shigella sonnei

Work A03.3 in HCC Buddy

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