K51
Ulcerative colitis
K51 is a non-billable ICD-10-CM code category for ulcerative colitis. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are K51.0 Ulcerative (chronic) pancolitis, K51.2 Ulcerative (chronic) proctitis, K51.3 Ulcerative (chronic) rectosigmoiditis, K51.4 Inflammatory polyps of colon and 3 more. Its coding notes include a Use additional code instruction, 3 Excludes1 entries and 8 Excludes2 entries.
Use additional code
Add the listed code as a secondary code, if known.
Excludes1
Not coded here. The listed conditions generally should not be reported together.
- Crohn's disease [regional enteritis] (K50.-)
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (8 notes)
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Includes
Further defines or gives examples of the content of the category.
Also from chapter/block level (1 note)
- noninfective inflammatory bowel disease