K59.31: Toxic megacolon
K59.31 is a billable, specific ICD-10-CM code for toxic megacolon. It is valid for submission on a claim.
Check K59.31 with the rest of the claim: free scrubberExcludes1 inherited from the categories above K59.31
A category’s note binds every code beneath it.
Written on K59.3: Megacolon, not elsewhere classified
Excludes2 inherited from the categories above K59.31
Not part of this code, but both may be coded when both are present.
Risk adjustment
K59.31 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:
- HCC 78 Intestinal Obstruction/Perforation0.326 RAF
Coefficient shown for the Community Non-dual Aged segment. A higher HCC in the same hierarchy will suppress this one, so capturing it does not always add score. Look up the whole chart to see which of its HCCs the hierarchy would zero.
Medicare coverage
K59.31 is named in 6 Medicare coverage policies: 6 listing it as supporting medical necessity. Which one applies depends on your Medicare contractor.
- A55937Billing and Coding: Diagnostic Colonoscopy
- A56394Billing and Coding: Colonoscopy and Sigmoidoscopy-Diagnostic
- A56421Billing and Coding: CT of the Abdomen and Pelvis
- A56456Billing and Coding: Colonoscopy/Sigmoidoscopy/Proctosigmoidoscopy
Alphabetic index entries that lead here
- Megacolon›toxic NEC
- Dilatation›colon›toxic
Code history
Unchanged in every release from FY2024 to FY2027.