C88.80
BillableOther malignant immunoproliferative diseases not having achieved remission
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C88.80 an HCC code?
Yes. C88.80 maps to Lymphoma and Other Cancers 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 C88.80
For C88.80to 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 C88.80 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C88.80 is the ICD-10-CM diagnosis code for other malignant immunoproliferative diseases not having achieved remission. Other rare blood or lymphoid cancers involving abnormal immune cell proliferation that have not responded adequately to treatment. C88.80 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, C88.80 maps to Lymphoma and Other Cancers (HCC 21) with a community, non-dual, aged base RAF weight of 0.671. Under the older V24 model, C88.80 mapped to the same category but with a base RAF weight of 0.675 — 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.
This is a catch-all code; use only when a more specific immunoproliferative disease code does not apply. Because C88.80 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 C88.80 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is a catch-all code; use only when a more specific immunoproliferative disease code does not apply
- •Provide detailed clinical documentation of the specific disease entity in the medical record for clarity
Clinical Significance
Other malignant immunoproliferative diseases not having achieved remission is a residual category for rare immunoproliferative neoplasms that do not fit into more specific subcategories such as Waldenstrom macroglobulinemia, heavy chain disease, or MALT lymphoma. These conditions involve pathologic proliferation of immune cells producing abnormal proteins and may include rare variants of lymphoplasmacytic disorders. Non-remission status indicates ongoing active disease.
Documentation Requirements
- ✓Documentation must clearly describe the specific immunoproliferative entity with pathology and immunohistochemistry supporting the diagnosis.
- ✓Laboratory studies including serum protein electrophoresis and immunofixation should be documented.
- ✓Justification for why a more specific code does not apply, treatment regimen, and non-remission status must be recorded.
Commonly Confused Codes
- •C88.81 (other malignant immunoproliferative diseases in remission) requires documented remission.
- •C88.00-C88.41 provide more specific codes for defined entities like Waldenstrom macroglobulinemia, heavy chain disease, IPSID, and MALT lymphoma.
- •C88.90 (malignant immunoproliferative disease, unspecified) is even less specific and should be avoided when possible.