ICD-10-CM 2027
ICD-10 code for megacolon
From the official ICD-10-CM alphabetic index entry “Megacolon (acquired) (functional) (not Hirschsprung's disease) (in)”. Page updated September 29, 2026.
About coding megacolon
The ICD-10-CM code for megacolon is K59.39 (Other megacolon). The official index lists 8 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on K59.39.
Within K59.3, choose K59.39 (Other megacolon) only when documentation doesn't support a more specific option: toxic megacolon (K59.31).
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 393 (Other Digestive System Diagnoses with MCC, relative weight 1.5881), DRG 394 (Other Digestive System Diagnoses with CC, relative weight 0.9228) and DRG 395 (Other Digestive System Diagnoses without CC/MCC, relative weight 0.6382), 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.
More specific megacolon codes (official index)
- Chagas' disease B57.32 — Megacolon in Chagas' disease
- congenital, congenitum (aganglionic) Q43.1 — Hirschsprung's disease
- Hirschsprung's (disease) Q43.1 — Hirschsprung's disease
- toxic NEC K59.31 — Toxic megacolon
- due to
- Clostridioides difficile
- not specified as recurrent A04.72 — Enterocolitis due to Clostridium difficile, not specified as recurrent
- recurrent A04.71 — Enterocolitis due to Clostridium difficile, recurrent
- Clostridium difficile
- not specified as recurrent A04.72 — Enterocolitis due to Clostridium difficile, not specified as recurrent
- recurrent A04.71 — Enterocolitis due to Clostridium difficile, recurrent
Common questions about megacolon ICD-10 codes
What is the ICD-10 code for megacolon?
- K59.39 — Other megacolon. More specific codes apply when the documentation supports them: B57.32, Q43.1, Q43.1, K59.31 and others below.
What is the ICD-10 code for chagas' disease megacolon?
- B57.32 — Megacolon in Chagas' disease.
What is the ICD-10 code for hirschsprung's megacolon?
- Q43.1 — Hirschsprung's disease.
What is the ICD-10 code for toxic nec megacolon?
- K59.31 — Toxic megacolon.
Is K59.39 billable?
- Yes. K59.39 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can K59.39 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict K59.39 as a principal diagnosis.
Is K59.39 a CC or MCC?
- K59.39 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.