ICD-10-CM 2027
ICD-10 code for shigellosis
From the official ICD-10-CM alphabetic index entry “Shigellosis”. Page updated September 29, 2026.
About coding shigellosis
The ICD-10-CM code for shigellosis is A03.9 (Shigellosis, unspecified). The official index lists 4 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on A03.9.
Within A03, choose A03.9 (unspecified) only when documentation doesn't support a more specific option: due to Shigella dysenteriae (A03.0), due to Shigella flexneri (A03.1), due to Shigella boydii (A03.2), due to Shigella sonnei (A03.3) and other shigellosis (A03.8).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 371 (Major Gastrointestinal Disorders and Peritoneal Infections with MCC, relative weight 1.7089), DRG 372 (Major Gastrointestinal Disorders and Peritoneal Infections with CC, relative weight 0.9964) and DRG 373 (Major Gastrointestinal Disorders and Peritoneal Infections without CC/MCC, relative weight 0.6941), in MDC 06 (Diseases and Disorders of the Digestive System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific shigellosis codes (official index)
Common questions about shigellosis ICD-10 codes
What is the ICD-10 code for shigellosis?
- A03.9 — Shigellosis, unspecified. More specific codes apply when the documentation supports them: A03.0, A03.1, A03.2, A03.3.
What is the ICD-10 code for group a shigellosis?
- A03.0 — Shigellosis due to Shigella dysenteriae.
What is the ICD-10 code for group b shigellosis?
- A03.1 — Shigellosis due to Shigella flexneri.
What is the ICD-10 code for group c shigellosis?
- A03.2 — Shigellosis due to Shigella boydii.
What is the ICD-10 code for group d shigellosis?
- A03.3 — Shigellosis due to Shigella sonnei.
Is A03.9 billable?
- Yes. A03.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can A03.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict A03.9 as a principal diagnosis.
Is A03.9 a CC or MCC?
- No. A03.9 is neither a CC nor an MCC under MS-DRG v44.0.