C84.93
BillableMature T/NK-cell lymphomas, unspecified, intra-abdominal lymph nodes
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C84.93 an HCC code?
Yes. C84.93 maps to Lung and Other Severe 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 C84.93
For C84.93 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 C84.93 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C84.93 is the ICD-10-CM diagnosis code for mature t/nk-cell lymphomas, unspecified, intra-abdominal lymph nodes. A mature T-cell or natural killer cell lymphoma affecting the lymph nodes in the abdominal cavity. C84.93 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, C84.93 maps to Lung and Other Severe Cancers (HCC 20) with a community, non-dual, aged base RAF weight of 0.000. Under the older CMS-HCC V24 model, C84.93 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.
Confirm intra-abdominal lymph node involvement through imaging studies or surgical findings. Because C84.93 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 C84.93 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Confirm intra-abdominal lymph node involvement through imaging studies or surgical findings
- •Document specific abdominal lymph node groups involved if available for clinical clarity
Clinical Significance
Mature T/NK-cell lymphomas, unspecified, involving intra-abdominal lymph nodes captures unclassified T/NK-cell lymphoma with abdominal nodal disease. Abdominal involvement can present with pain, obstruction, or constitutional symptoms. This code emphasizes the need for further pathologic workup to determine the specific T-cell lymphoma subtype for optimal treatment selection.
Documentation Requirements
- ✓Pathology confirming mature T-cell or NK-cell lymphoma lineage
- ✓Abdominal imaging documenting lymph node involvement
- ✓Immunophenotyping results showing T-cell or NK-cell markers
- ✓Documentation of why further subtype classification was not possible
- ✓Clinical staging
Commonly Confused Codes
- •C84.43 — PTCL-NOS, intra-abdominal: More specific diagnosis of exclusion
- •C84.63/C84.73 — ALCL ALK-positive/negative, intra-abdominal: Specific subtype if ALCL morphology confirmed
- •C86.2 — Enteropathy-associated T-cell lymphoma: Specific GI-associated T-cell lymphoma
- •C84.97 — Mature T/NK-cell lymphoma, unspecified, spleen: Splenic involvement has its own code