A08.11 Acute gastroenteropathy due to Norwalk agent

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applicable to

• Acute gastroenteropathy due to Norovirus
• Acute gastroenteropathy due to Norwalk-like agent

Applies from A08 Viral and other specified intestinal infections

Excludes1 (never code together)

• influenza with involvement of gastrointestinal tract (J09.X3, J10.2, J11.2)

MS-DRG index

Defines the logic of DRG(s) 391-392 in MDC 06.

Approximate ICD-9-CM (GEMs)

• 008.63 Enteritis due to norwalk virus (approximate)

Code annotations containing back-references to A08.11

Back-references to A08

• Type 1 Excludes: J09.X3 Influenza due to identified novel influenza A virus with gastrointestinal manifestations ("'intestinal flu' [viral gastroenteritis] (A08.-)")
• Type 1 Excludes: J10.2 Influenza due to other identified influenza virus with gastrointestinal manifestations ("'intestinal flu' [viral gastroenteritis] (A08.-)")
• Type 1 Excludes: J11.2 Influenza due to unidentified influenza virus with gastrointestinal manifestations ("'intestinal flu' [viral gastroenteritis] (A08.-)")
• Type 2 Excludes: P37 Other congenital infectious and parasitic diseases ("infectious neonatal diarrhea (A00-A09)")

Diagnosis Index entries for A08.11

• Enteritis (acute) (diarrheal) (hemorrhagic) (noninfective) › norovirus
• Gastroenteritis (acute) (chronic) (noninfectious) › viral NEC › acute infectious › type Norwalk
• Gastroenteritis (acute) (chronic) (noninfectious) › viral NEC › Norwalk agent
• Gastroenteropathy › acute, due to Norwalk agent
• Gastroenteropathy › acute, due to Norovirus

Nearby codes

• A08 Viral and other specified intestinal infections
• A08.0 Rotaviral enteritis
• A08.1 Acute gastroenteropathy due to Norwalk agent and other small round viruses
• A08.11 Acute gastroenteropathy due to Norwalk agent (this code)
• A08.19 Acute gastroenteropathy due to other small round viruses
• A08.2 Adenoviral enteritis
• A08.3 Other viral enteritis
• A08.31 Calicivirus enteritis
• A08.32 Astrovirus enteritis