ICD-10-CM · Chapter 1 · A00-B99
A09 Infectious gastroenteritis and colitis, unspecified
Includes
- Infectious colitis NOS
- Infectious enteritis NOS
- Infectious gastroenteritis NOS
Excludes 1 (cannot be coded together)
- colitis NOS (K52.9)
- diarrhea NOS (R19.7)
- enteritis NOS (K52.9)
- gastroenteritis NOS (K52.9)
- noninfective gastroenteritis and colitis, unspecified (K52.9)
This category is a complete, billable diagnosis code.
No additional specificity is required — submit A09 directly on claims and documentation without a subcode extension.
Last reviewed: September 2026