ICD-10 K51
Non-Billable HeaderUlcerative colitis
About ICD-10-CM K51
ICD-10-CM code K51 represents Ulcerative colitis. This is a non-billable header code in the Digestive System chapter (block K51). The 2026 edition of ICD-10-CM K51 became effective on October 1, 2025. Non-billable codes cannot be used as a primary or secondary diagnosis on a claim, use a more specific child code instead.
Type 1 Excludes
Pure excludes, these codes can never be coded together with K51. The conditions are mutually exclusive (e.g., congenital vs acquired forms).
- Crohn's disease [regional enteritis] (K50.-)
Use Additional Code
When coding K51, also report these additional codes when applicable.
- code to identify any associated fistulas, if applicable:
- anal fistula (K60.3-)
- anorectal fistula (K60.5-)
- rectal fistula (K60.4-)
Medicare LCD Coverage for K51
Local Coverage Determinations (LCDs) from CMS MACs that list K51 as a covered diagnosis.
This doesn't mean the code isn't covered, it means no MAC has issued a Local Coverage Determination naming this specific code. Coverage may still apply under National Coverage Determinations or general medical-necessity rules.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing K51.
Our payer policy database covers Aetna, Cigna, Anthem, BCBS, Humana, and Medicare Advantage plans, but K51 doesn't currently appear in any indexed policy. The code may still be covered under standard plan benefits.
CPT Codes Commonly Billed with K51
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
We don't have CPT pairings indexed for this specific code yet. Use the CPT search above to find common procedures, or check your payer's published medical policy for code-specific guidance.
Codes Adjacent To K51
Other codes in section K50-K52 (Noninfective enteritis and colitis).
ICD-10 K51, Billing FAQ
Is ICD-10 code K51 billable? +
No, K51 is a non-billable header code. Use a more specific child code from block K51 when submitting claims.
What codes are Type 1 Excludes for K51? +
Type 1 Excludes (never code together with K51): Crohn's disease [regional enteritis] (K50.-)
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on June 1, 2026.
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