What is ICD-10 code K51.914?

K51.914 is the ICD-10-CM diagnosis code for Ulcerative colitis, unspecified with abscess. Ulcerative colitis of unspecified extent with a localized collection of pus (abscess) in the colon or surrounding tissues. It belongs to the ICD-10-CM chapter for diseases of the digestive system (k00-k95). K51.914 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. K51.914 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. K51.914 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. K51.914 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

What is the V28 vs V24 difference for K51.914?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. For K51.914, V28 maps to Ulcerative Colitis at RAF 0.244 while V24 mapped to Inflammatory Bowel Disease at RAF 0.308. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting K51.914?

Document the location of the abscess (intramural, pericolic, etc.) and whether it has been drained or treated. An abscess may indicate more severe disease and could warrant additional imaging or intervention codes. Because K51.914 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score.

2026 ICD-10-CM K51.914: Ulcerative colitis

ICD-10-CM Code View

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Code lookupK51.914Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the digestive system (K00-K95) / Noninfective enteritis and colitis (K50-K52)

K51.914

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Ulcerative colitis, unspecified with abscess

Ulcerative colitis of unspecified extent with a localized collection of pus (abscess) in the colon or surrounding tissues.

Buddy Insight

Ulcerative colitis, unspecified, with abscess indicates an infectious complication of ulcerative colitis of undetermined extent.

CMS-HCC V28

Mapped

HCC 81

Ulcerative Colitis

RAF 0.244

CMS-HCC V24

Mapped

HCC 35

Inflammatory Bowel Disease

RAF 0.308

ACA/HHS

Mapped

HCC 48

HHS-HCC 48

Varies by metal level

ESRD/PACE

Mapped

HCC 35

Inflammatory Bowel Disease

RAF 0.048

RXHCC

Mapped

HCC 67

Inflammatory Bowel Disease

RAF 0.494

Code Book Path

Official

K51.9Ulcerative colitis, unspecified

K51.91Ulcerative colitis, unspecified, with complications

K51.914Ulcerative colitis, unspecified with abscess

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for K51.914 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for K51.914 in this effective period.

Related Child Codes

Official

K51.911Ulcerative colitis, unspecified with rectal bleeding

K51.912Ulcerative colitis, unspecified with intestinal obstruction

K51.913Ulcerative colitis, unspecified with fistula

K51.918Ulcerative colitis, unspecified with other complication

K51.919Ulcerative colitis, unspecified with unspecified complications

Includes

Official

ICD-10-CM does not list Includes notes for K51.914 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for K51.914 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for K51.914 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for K51.914 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for K51.914 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Confirmed ulcerative colitis diagnosis

Imaging evidence of abscess with location and size

Provider statement linking abscess to the colitis

Treatment plan including antibiotics and drainage if indicated

MEAT Support

HCC Buddy guidance

Confirmed ulcerative colitis diagnosis

Imaging evidence of abscess with location and size

Provider statement linking abscess to the colitis

Treatment plan including antibiotics and drainage if indicated

Audit Caution

HCC Buddy guidance

Using this unspecified code when imaging for the abscess reveals the disease extent

Coding abscess separately instead of using the combination code

Not linking the abscess to the underlying colitis

Using uncomplicated codes when abscess is present

Common Mistakes

HCC Buddy guidance

K51.914 vs K63.0 — K63.0 is abscess of intestine unrelated to inflammatory bowel disease

K51.914 vs K61.x — K61 codes are for perianal/anorectal abscess not caused by inflammatory bowel disease

K51.914 vs K51.014/K51.214/K51.314/K51.514/K51.814 — Use extent-specific codes when known

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is K51.914 an HCC code?

Yes. K51.914 (Ulcerative colitis, unspecified with abscess) maps to Ulcerative Colitis under the CMS-HCC V28 risk adjustment model (and Inflammatory Bowel Disease under V24), with a community non-dual aged RAF of 0.244. It is billable for payment year 2026.

Coder answer: K51.914 is billable and maps to V28 HCC 81, Ulcerative Colitis. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: K51.914
Description: Ulcerative colitis, unspecified with abscess
HCC (V28): HCC 81 — Ulcerative Colitis
RAF: 0.244
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 81, Ulcerative Colitis

0.244

V24HCC 35, Inflammatory Bowel Disease

0.308

ESRDHCC 35, Inflammatory Bowel Disease

0.048

RxHCCHCC 67, Inflammatory Bowel Disease

0.494

Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

Work K51.914 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for K51.914

For K51.914 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed K51.914 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

K51.914 is the ICD-10-CM diagnosis code for ulcerative colitis, unspecified with abscess. Ulcerative colitis of unspecified extent with a localized collection of pus (abscess) in the colon or surrounding tissues. K51.914 sits in the ICD-10-CM chapter for diseases of the digestive system (k00-k95), within the section covering noninfective enteritis and colitis (k50-k52).

Under the CMS-HCC V28 risk adjustment model, K51.914 maps to Ulcerative Colitis (HCC 81) with a community, non-dual, aged base RAF weight of 0.244. Under the older CMS-HCC V24 model, K51.914 maps to Inflammatory Bowel Disease (HCC 35) with a community, non-dual, aged base RAF weight of 0.308. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.

Document the location of the abscess (intramural, pericolic, etc.) and whether it has been drained or treated. Because K51.914 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for K51.914 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Document the location of the abscess (intramural, pericolic, etc.) and whether it has been drained or treated.
•An abscess may indicate more severe disease and could warrant additional imaging or intervention codes.

Clinical Significance

Ulcerative colitis, unspecified, with abscess indicates an infectious complication of ulcerative colitis of undetermined extent. The abscess represents a serious complication requiring antibiotics and potentially drainage, while imaging for the abscess should also help determine disease extent for more specific coding.

Documentation Requirements

✓Confirmed ulcerative colitis diagnosis
✓Imaging evidence of abscess with location and size
✓Provider statement linking abscess to the colitis
✓Treatment plan including antibiotics and drainage if indicated
✓Culture results if drainage was performed
✓Plan to determine disease extent

Commonly Confused Codes

•K51.914 vs K63.0: K63.0 is abscess of intestine unrelated to inflammatory bowel disease
•K51.914 vs K61.x: K61 codes are for perianal/anorectal abscess not caused by inflammatory bowel disease
•K51.914 vs K51.014/K51.214/K51.314/K51.514/K51.814: Use extent-specific codes when known