C83.59
BillableLymphoblastic (diffuse) lymphoma, extranodal and solid organ sites
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C83.59 an HCC code?
Yes. C83.59 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 C83.59
For C83.59 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 C83.59 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C83.59 is the ICD-10-CM diagnosis code for lymphoblastic (diffuse) lymphoma, extranodal and solid organ sites. A type of blood cancer (lymphoblastic lymphoma) that has spread to organs outside the lymph node system, such as the liver, lungs, or other solid organs. C83.59 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, C83.59 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, C83.59 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 code requires documentation of the specific extranodal or solid organ site involved; review pathology reports for site confirmation. Because C83.59 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 C83.59 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This code requires documentation of the specific extranodal or solid organ site involved; review pathology reports for site confirmation
- •Do not use this code if the lymphoma is limited to lymph nodes; verify extranodal involvement is documented
Clinical Significance
Lymphoblastic lymphoma of extranodal and solid organ sites indicates disease involvement beyond the lymph node system, which may include bone marrow (below leukemia threshold), liver, skin, gonads, or other organs. Extranodal involvement often indicates more advanced disease and may require modification of treatment intensity.
Documentation Requirements
- ✓Pathology confirmation from the specific extranodal site with TdT staining
- ✓Documentation of specific organ(s) involved
- ✓Bone marrow biopsy with blast percentage documented (must be <25% for lymphoma designation)
- ✓Imaging confirming extranodal involvement
- ✓CNS evaluation for occult involvement
Commonly Confused Codes
- •C83.57 — Lymphoblastic lymphoma, spleen; splenic involvement has its own specific code
- •C83.58 — Multiple nodal sites; C83.59 is for non-nodal organ involvement
- •C91.00 — Acute lymphoblastic leukemia; bone marrow blasts >25% means leukemia, not extranodal lymphoma
- •C83.398 — DLBCL, extranodal; mature vs. immature cell distinction