A03.9 — Shigellosis, unspecified
Is A03.9 billable?
Yes, but A03.9 is an unspecified code. A03.9 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, A03.9 is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting A03.9 — the more specific alternatives are listed below.
A03.9 at a glance
| Code | A03.9 |
|---|---|
| Description | Shigellosis, unspecified |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does A03.9 group to?
A03.9 sits in MDC 06 and helps define the logic of 3 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 371Major Gastrointestinal Disorders and Peritoneal Infections with MCCmedical
- 372Major Gastrointestinal Disorders and Peritoneal Infections with CCmedical
- 373Major Gastrointestinal Disorders and Peritoneal Infections without CC/MCCmedical
How is A03.9 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to A03.9. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Chinese dysentery
- Shigellosis
- Dysentery, dysenteric › bacillary (catarrhal) (diarrhea) (epidemic) (hemorrhagic) (infectious) (sporadic) (tropical)
- Dysentery, dysenteric › Chinese (catarrhal) (diarrhea) (epidemic) (hemorrhagic) (infectious) (sporadic) (tropical)
- Enteritis › bacillary NOS (acute) (diarrheal) (hemorrhagic) (noninfective)
- Infection, infected, infective › Shigella (opportunistic)
- Sepsis › Shigella (generalized) (unspecified organism)
- Dysentery, dysenteric › arthritis › bacillary (catarrhal) (diarrhea) (epidemic) (hemorrhagic) (infectious) (sporadic) (tropical)
- Dysentery, dysenteric › bacillary › arthritis (catarrhal) (diarrhea) (epidemic) (hemorrhagic) (infectious) (sporadic) (tropical)
- Dysentery, dysenteric › bacillary › Shigella (catarrhal) (diarrhea) (epidemic) (hemorrhagic) (infectious) (sporadic) (tropical)
Inclusion terms
Alternative wording in documentation that is classified to A03.9.
- Bacillary dysentery NOS
Use additional code — inherited from Chapter 1
Report an additional code alongside A03.9 to fully describe the condition. A03.9 is sequenced first.
- code to identify resistance to antimicrobial drugs (Z16.-)
Excludes2 — not included here — inherited from Chapter 1
The conditions below are not part of A03.9, but a patient may have both at the same time. When documentation supports it, A03.9 and the excluded code may both be reported.
- carrier or suspected carrier of infectious disease (Z22.-)
- certain localized infections - see body system-related chapters
- infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
- infectious and parasitic diseases specific to the perinatal period (P35-P39)
- influenza and other acute respiratory infections (J00-J22)
How long has A03.9 existed?
A03.9 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.