C91.30
BillableProlymphocytic leukemia of B-cell type not having achieved remission
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C91.30 an HCC code?
Yes. C91.30 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 C91.30
For C91.30to 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 C91.30 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C91.30 is the ICD-10-CM diagnosis code for prolymphocytic leukemia of b-cell type not having achieved remission. A rare blood cancer (prolymphocytic leukemia) affecting B-cells that has not responded to or achieved remission from treatment. C91.30 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, C91.30 maps to Lymphoma and Other Cancers (HCC 19) with a community, non-dual, aged base RAF weight of 0.105. Under the older V24 model, C91.30 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.
The fifth character '0' indicates no remission achieved - document treatment response status clearly. Because C91.30 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 C91.30 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •The fifth character '0' indicates no remission achieved - document treatment response status clearly
- •Prolymphocytic leukemia is distinct from chronic lymphocytic leukemia; verify correct diagnosis before coding
Clinical Significance
Prolymphocytic leukemia of B-cell type (B-PLL) is a rare and aggressive lymphoid neoplasm characterized by a high white blood cell count with more than 55% prolymphocytes in peripheral blood. B-PLL has a worse prognosis than typical CLL and often presents with massive splenomegaly and minimal lymphadenopathy. The 'not in remission' status indicates ongoing active disease despite potential treatment attempts.
Documentation Requirements
- ✓Documentation must confirm the prolymphocytic morphology and B-cell immunophenotype, typically showing strong surface immunoglobulin expression.
- ✓The diagnosis should be supported by peripheral blood smear and/or bone marrow biopsy showing prolymphocyte predominance.
- ✓Disease status as not in remission must be explicitly stated, along with treatment history and current disease burden.
Commonly Confused Codes
- •C91.10 (B-CLL not in remission) is the most common confusion -
- •B-PLL has distinct morphology with larger cells and prominent nucleoli. C91.60 (T-cell PLL not in remission) is the T-cell counterpart. C91.Z0 (other lymphoid leukemia not in remission) should not be used when B-PLL is specifically diagnosed. Some cases of CLL with prolymphocytic transformation should still be coded under CLL.