ICD-10-CM > K00-K95 > K80-K87 > K81 K81 Cholecystitis Non-Billable/Non-Specific Use Additional code if applicable for associated gangrene of gallbladder (K82.A1), or perforation of gallbladder (K82.A2) Type 1 Excludes cholecystitis with cholelithiasis (K80.-) Codes K81.0Acute cholecystitisK81.1Chronic cholecystitisK81.2Acute cholecystitis with chronic cholecystitisK81.9Cholecystitis, unspecified