ICD10
ICD-10 Code K51.9: Ulcerative colitis, unspecified
Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026
What is this code?
ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Diseases of the digestive system (K00-K95).
When is it used?
- May be used when a clinician documents ulcerative colitis, unspecified in a patient's medical record.
- May appear in hospital records, claims, referrals, and clinical documentation.
- This code may act more like a grouping or parent code, so a more specific child code may be used in final documentation when available.
What it does not mean
- A code alone does not explain severity, treatment plan, or outcome.
- A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
- This entry may represent a broader category rather than the most specific billable code.
Code hierarchy
chapter
11Diseases of the digestive system (K00-K95)
block
K50-K52Noninfective enteritis and colitis
category
K51Ulcerative colitis
currentK51
Where you may see this code
You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen.
Related specialists
GastroenterologistGeneral Physician
Sibling codes
Mapped diagnoses and classifications
SNOMED_CT 969688801000119108high
Acute left-sided ulcerative colitis
Source: SNOMED International ICD-10 map
SNOMED_CT 128600008high
Acute ulcerative colitis
Source: SNOMED International ICD-10 map
SNOMED_CT 109814008high
Acute ulcerative gastroenteritis complicating pneumonia
Source: SNOMED International ICD-10 map
SNOMED_CT 201727001high
Arthropathy in ulcerative colitis
Source: SNOMED International ICD-10 map
SNOMED_CT 441971007high
Chronic left-sided ulcerative colitis
Source: SNOMED International ICD-10 map
SNOMED_CT 444546002high
Chronic ulcerative colitis
Source: SNOMED International ICD-10 map
Coding guidelines
Compatibility
Legacy code aligns to an official FY 2026 category. Frontend should resolve to the official category page and surface the billable child codes.
Legacy codes
K51.9
Replacement codes
K51.90 — Ulcerative colitis, unspecified, without complications
Common synonyms
Ulcerative colitis, unspecifiedUlcerative colitis
Frequently asked questions
About this content
This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.