K51.90 — Ulcerative colitis, unspecified, without complications
K51.90 is a billable, specific ICD-10-CM code for ulcerative colitis, unspecified, without complications. It is valid for submission on a claim.
Risk adjustment
K51.90 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:
- HCC 81 Ulcerative Colitis0.244 RAF
Coefficient shown for the Community Non-dual Aged segment. A higher HCC in the same hierarchy will suppress this one, so capturing it does not always add score.
Medicare coverage
K51.90 is named in 23 Medicare coverage policies — 23 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A52423Billing and Coding: Infliximab and biosimilars
- A52423Billing and Coding: Infliximab and biosimilars
- A55717Billing and Coding: Lab: Flow Cytometry
- A55937Billing and Coding: Diagnostic Colonoscopy
How K51.90 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to K51.90.
- Colitis›ulcerative(chronic)
- Arthropathy›in›ulcerative colitis NEC
Related codes at this level
Codes that share K51.9. If K51.90 is not quite right, the correct code is usually one of these.
Questions about K51.90
- Is K51.90 a billable ICD-10-CM code?
- Yes. K51.90 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does K51.90 sit in the tabular list?
- Diseases of the digestive system (K00-K95), in the block Noninfective enteritis and colitis (K50-K52).