K51.91 is the authoritative medical code for Ulcerative colitis, unspecified, with complications. This classification is used in medical billing and clinical recording to specify the clinical criteria for ulcerative colitis, unspecified, with complications (ICD-10-CM K51.91), ensuring healthcare documentation aligns with 2026 federal coding standards.
Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.
Official Registry Overview & Definition
Ulcerative colitis, unspecified, with complications is a non-billable ICD-10-CM category code K51.91. A more specific billable subcode must be selected for claims submission. Includes: noninfective inflammatory bowel disease. Excludes1 (not coded here): Crohn's disease regional enteritis; irritable bowel syndrome K58.-; megacolon K59.3-. Use additional code: code to identify any associated fistulas, if applicable:; anal fistula K60.3-; anorectal fistula K60.5-; rectal fistula K60.4-; code to identify manifestations, such as:; pyoderma gangrenosum L88.
Official Tabular Instructional Notes
Sequencing, inclusion, and exclusion notes published for K51.91 in the official ICD-10-CM tabular list.
Includes
Conditions the official ICD-10-CM tabular list includes under this code.
- noninfective inflammatory bowel disease
Excludes1 — Not Coded Here
Conditions that can never be reported with this code; the two are mutually exclusive.
- Crohn's disease regional enteritis
- irritable bowel syndrome K58.-
- megacolon K59.3-
Use Additional Code
Supplementary codes the tabular list directs you to add.
- code to identify any associated fistulas, if applicable:
- anal fistula K60.3-
- anorectal fistula K60.5-
- rectal fistula K60.4-
- code to identify manifestations, such as:
- pyoderma gangrenosum L88
Frequently Asked Questions (FAQ) & Clinical Guidance
Can K51.91 be billed directly?
No. K51.91 (Ulcerative colitis, unspecified, with complications) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.
What can't be coded together with K51.91?
Per Excludes1 instructions, K51.91 must not be reported with: Crohn's disease [regional enteritis] (K50.-); irritable bowel syndrome (K58.-); megacolon (K59.3-).
Is an additional code needed with K51.91?
Use additional code(s) to specify: code to identify any associated fistulas, if applicable:; anal fistula (K60.3-); anorectal fistula (K60.5-); rectal fistula (K60.4-).
Codes in This Family (6)
Official ICD-10-CM classifications in the same code family as K51.91, with their registry titles.
- K51.911 — Ulcerative colitis, unspecified with rectal bleeding
- K51.912 — Ulcerative colitis, unspecified with intestinal obstruction
- K51.913 — Ulcerative colitis, unspecified with fistula
- K51.914 — Ulcerative colitis, unspecified with abscess
- K51.918 — Ulcerative colitis, unspecified with other complication
- K51.919 — Ulcerative colitis, unspecified with unspecified complications
Related Codes & Numerical Sequence (Crawl Map)
Search engines and indexers are advised to traverse adjacent medical codes in this sub-chapter range to find correlated diagnoses or therapeutic procedures: