C83.398
BillableDiffuse large B-cell lymphoma of other 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 C83.398 an HCC code?
Yes. C83.398 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 C83.398
For C83.398to 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 C83.398 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C83.398 is the ICD-10-CM diagnosis code for diffuse large b-cell lymphoma of other extranodal and solid organ sites. A type of aggressive blood cancer (diffuse large B-cell lymphoma) affecting organs or tissues outside the lymph node system in locations not specified elsewhere. C83.398 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, C83.398 maps to Lung and Other Severe Cancers (HCC 20) with a community, non-dual, aged base RAF weight of 1.136. Under the older CMS-HCC V24 model, C83.398 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 is an extranodal site code; clearly document which specific organ or tissue is involved (e.g., liver, bone, GI tract). Because C83.398 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 C83.398 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is an extranodal site code; clearly document which specific organ or tissue is involved (e.g., liver, bone, GI tract)
- •Ensure the involved site is not better described by a more specific anatomical code before using this catch-all code
Clinical Significance
DLBCL of other extranodal and solid organ sites captures disease involving organs outside the lymph node system, excluding the CNS (which has its own code). Common extranodal DLBCL sites include the GI tract, bone, testis, breast, and skin. Extranodal DLBCL may have different biology and prognosis depending on the organ involved.
Documentation Requirements
- ✓Pathology confirmation from the specific extranodal site (organ biopsy)
- ✓Documentation of the specific organ(s) involved
- ✓Imaging confirming extranodal involvement
- ✓Assessment for primary extranodal vs. secondary involvement from nodal disease
- ✓Bone marrow biopsy results if marrow involvement suspected
Commonly Confused Codes
- •C83.390 — Primary CNS lymphoma; use this separate code for CNS DLBCL, not C83.398
- •C83.37 — DLBCL, spleen; splenic involvement has its own specific code
- •C83.38 — DLBCL, multiple lymph node sites; C83.398 is for non-nodal sites
- •C83.30 — DLBCL, unspecified; use C83.398 when extranodal involvement is specifically documented