ICD-10 Code K51.918 – Ulcerative colitis, unspecified with other complication (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K51.918 – Ulcerative colitis, unspecified with other complication
What it is
K51.918 identifies ulcerative colitis when the type is not further specified and another complication is documented. Use it when the record confirms ulcerative colitis but does not name a more specific subtype.
Clinical signs
Clinical features vary; refer to documentation. Typical ulcerative colitis findings include chronic colonic inflammation with abdominal pain, diarrhea, rectal bleeding, urgency, or mucus passage, along with a documented complication.
When to use this code
Use this code when the provider documents ulcerative colitis and an additional complication, but the chart does not specify a more precise colitis type or complication code. Check documentation for the exact complication and any available site or severity details.
If the note only says ulcerative colitis without further detail, this code is not the best choice. Code the documented complication separately when required, and follow any sequencing instructions in the record.
Do not use for
Do not use this code for Crohn disease, infectious colitis, or ulcerative colitis without a documented complication. Check documentation if the complication is not clearly stated.
Coding tip
Assign K51.918 only after confirming both ulcerative colitis and another complication in the provider’s documentation.