K28.1 ICD-10-CM Code: Acute gastrojejunal ulcer with perforation
K28.1 maps to CMS-HCC V28 78 (RAF 0.326). Documentation must support MEAT. MEAT criteria · RAF calculator · HCC Buddy coding tools
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FY 2026 Apr update / Diseases of the digestive system (K00-K95) / Diseases of esophagus, stomach and duodenum (K20-K31)
K28.1
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceAcute gastrojejunal ulcer with perforation
A sudden gastrojejunal ulcer with a hole or rupture in the stomach or intestinal wall.
Buddy Insight
Acute gastrojejunal ulcer with perforation is a surgical emergency occurring at the gastrojejunal anastomosis, typically as a complication of prior gastric surgery (e.
CMS-HCC V28
MappedHCC 78
RAF 0.326
CMS-HCC V24
MappedHCC 33
RAF 0.219
ACA/HHS
MappedHCC 42
Varies by metal level
ESRD/PACE
MappedHCC 33
RAF 0.078
RXHCC
N/A—
Not mapped
Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for K28.1 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for K28.1 in this effective period.
Related Child Codes
Includes
Official- anastomotic ulcer (peptic) or erosion
- gastrocolic ulcer (peptic) or erosion
- gastrointestinal ulcer (peptic) or erosion
- gastrojejunal ulcer (peptic) or erosion
- jejunal ulcer (peptic) or erosion
Excludes 1
Official- primary ulcer of small intestine (K63.3)
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for K28.1 in this effective period.
Use Additional
Official- code to identify:
- alcohol abuse and dependence (F10.-)
Code Also
OfficialICD-10-CM does not list Code Also instructions for K28.1 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
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 K28.1 an HCC code?
Yes. K28.1 (Acute gastrojejunal ulcer with perforation) maps to Intestinal Obstruction/Perforation under the CMS-HCC V28 risk adjustment model (and Intestinal Obstruction/Perforation under V24), with a community non-dual aged RAF of 0.326. It is billable for payment year 2026.
Coder answer: K28.1 is billable and maps to V28 HCC 78, Intestinal Obstruction/Perforation. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.
- Code
- K28.1
- Description
- Acute gastrojejunal ulcer with perforation
- HCC (V28)
- HCC 78 — Intestinal Obstruction/Perforation
- RAF
- 0.326
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
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 K28.1 in the Code Book — tabular path, V28 RAF, and MEAT checklist →
MEAT Criteria for K28.1
For K28.1 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 K28.1 during that encounter, not just copy-forwarded from a problem list.
Coder workflow notes
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What This Code Means
K28.1 is the ICD-10-CM diagnosis code for acute gastrojejunal ulcer with perforation. A sudden gastrojejunal ulcer with a hole or rupture in the stomach or intestinal wall. K28.1 sits in the ICD-10-CM chapter for diseases of the digestive system (k00-k95), within the section covering diseases of esophagus, stomach and duodenum (k20-k31).
Under the CMS-HCC V28 risk adjustment model, K28.1 maps to Intestinal Obstruction/Perforation (HCC 78) with a community, non-dual, aged base RAF weight of 0.326. Under the older V24 model, K28.1 mapped to the same category but with a base RAF weight of 0.219, V28 recalibrated weights across the entire model. 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.
Perforation is a serious complication requiring urgent intervention; confirm perforation is documented before coding. Because K28.1 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 K28.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Perforation is a serious complication requiring urgent intervention; confirm perforation is documented before coding
- •Do not use this code if hemorrhage is also present; use K28.2 instead
Clinical Significance
Acute gastrojejunal ulcer with perforation is a surgical emergency occurring at the gastrojejunal anastomosis, typically as a complication of prior gastric surgery (e.g., Billroth procedures or gastric bypass). The perforation at this surgical site carries unique risks including anastomotic leak and peritonitis. This code specifically identifies the marginal ulcer complication in post-surgical patients.
Documentation Requirements
- ✓Provider documentation of acute gastrojejunal (marginal/stomal) ulcer with perforation
- ✓Surgical history confirming prior gastric surgery with gastrojejunal anastomosis
- ✓Evidence of perforation at the anastomotic site
- ✓Acuity confirmed as acute
- ✓Operative findings and surgical repair documentation
Commonly Confused Codes
- •K28.0: Acute gastrojejunal ulcer with hemorrhage: bleeding only, no perforation
- •K28.2: Acute gastrojejunal ulcer with both hemorrhage and perforation: use when both present
- •K28.5: Chronic or unspecified gastrojejunal ulcer with perforation: chronic or unspecified acuity
- •K25.1: Acute gastric ulcer with perforation: native stomach ulcer, not at anastomotic site
- •K91.1: Postgastric surgery syndromes: a broader post-surgical category, not specific to ulcer perforation