ICD-10-CM 2027
ICD-10 code for protozoal colitis
From the official ICD-10-CM alphabetic index entry “Colitis (acute) (catarrhal) (chronic) (noninfective) (hemorrhagic) › protozoal”. Page updated September 29, 2026.
About coding protozoal colitis
The ICD-10-CM code for protozoal colitis is A07.9 (Protozoal intestinal disease, unspecified).
Within A07, choose A07.9 (Protozoal intestinal disease, unspecified) only when documentation doesn't support a more specific option: Balantidiasis (A07.0), Giardiasis [lambliasis] (A07.1), Cryptosporidiosis (A07.2), Isosporiasis (A07.3), Cyclosporiasis (A07.4) and other specified protozoal intestinal diseases (A07.8).
As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.
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.
Common questions about protozoal colitis ICD-10 codes
What is the ICD-10 code for protozoal colitis?
- A07.9 — Protozoal intestinal disease, unspecified.
Is A07.9 billable?
- Yes. A07.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can A07.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict A07.9 as a principal diagnosis.
Is A07.9 a CC or MCC?
- A07.9 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.