C88.30
BillableImmunoproliferative small intestinal disease not having achieved remission
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C88.30 an HCC code?
Yes. C88.30 maps to Breast, Prostate, Colorectal and Other Cancers and Tumors under the CMS-HCC V28 risk adjustment model (and Lymphoma and Other Cancers under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. 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.
MEAT Criteria for C88.30
For C88.30 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 C88.30 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C88.30 is the ICD-10-CM diagnosis code for immunoproliferative small intestinal disease not having achieved remission. A rare intestinal cancer involving abnormal lymphoid tissue in the small intestine that has not responded adequately to treatment. C88.30 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of lymphoid, hematopoietic and related tissue (c81-c96).
Under the CMS-HCC V28 risk adjustment model, C88.30 maps to Breast, Prostate, Colorectal and Other Cancers and Tumors (HCC 21) with a community, non-dual, aged base RAF weight of 0.545. Under the older CMS-HCC V24 model, C88.30 maps to Lymphoma and Other Cancers (HCC 10) with a community, non-dual, aged base RAF weight of 0.675. 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.
This condition is associated with chronic antigenic stimulation; document any underlying infections or autoimmune conditions. Because C88.30 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 C88.30 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This condition is associated with chronic antigenic stimulation; document any underlying infections or autoimmune conditions
- •Distinguish remission status carefully as it affects treatment planning and prognosis
Clinical Significance
Immunoproliferative small intestinal disease (IPSID), also known as alpha heavy chain disease of the intestine or Mediterranean lymphoma, is a rare B-cell lymphoma affecting the small intestinal mucosa and mesenteric lymph nodes. It is most prevalent in developing countries and is associated with chronic antigenic stimulation, often linked to Campylobacter jejuni infection. Non-remission status indicates the disease continues despite treatment.
Documentation Requirements
- ✓Documentation must include endoscopic biopsy findings showing diffuse lymphoplasmacytic infiltration of the small intestinal mucosa, with immunohistochemistry results.
- ✓Alpha heavy chain presence in serum should be confirmed if applicable.
- ✓Nutritional status assessment, malabsorption workup, infection screening, treatment regimen, and non-remission status must be documented.
Commonly Confused Codes
- •C88.31 (IPSID in remission) requires documented remission.
- •K90.0 (celiac disease) causes similar malabsorption but is non-malignant.
- •C86.20 (enteropathy-type T-cell lymphoma) is a T-cell lymphoma of the intestine, not a B-cell proliferation.
- •C88.40 (MALT lymphoma) is related but represents a different stage of mucosal lymphoid malignancy.