C85.99
BillableNon-Hodgkin lymphoma, unspecified, 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 C85.99 an HCC code?
Yes. C85.99 maps to Breast, Prostate, Colorectal and Other Cancers and Tumors 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 C85.99
For C85.99 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 C85.99 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C85.99 is the ICD-10-CM diagnosis code for non-hodgkin lymphoma, unspecified, extranodal and solid organ sites. Non-Hodgkin lymphoma of unspecified type affecting organs or tissues outside the lymph node system. C85.99 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, C85.99 maps to Breast, Prostate, Colorectal and Other Cancers and Tumors (HCC 21) with a community, non-dual, aged base RAF weight of 0.545. Under the older CMS-HCC V24 model, C85.99 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.
Extranodal sites include organs like liver, bone, GI tract, CNS, and other solid organs. Because C85.99 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 C85.99 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Extranodal sites include organs like liver, bone, GI tract, CNS, and other solid organs
- •Specify which organ(s) are involved in documentation for optimal coding accuracy
Clinical Significance
Non-Hodgkin lymphoma of unspecified type affecting extranodal and solid organ sites represents lymphoma arising in or primarily involving organs outside the lymph node system, such as the gastrointestinal tract, central nervous system, liver, bone, or skin. Extranodal NHL accounts for approximately one-third of all NHL cases and may present with organ-specific symptoms that mimic non-malignant conditions. Prognosis and treatment vary significantly depending on the organ involved.
Documentation Requirements
- ✓Provider must specify which extranodal organ or solid organ site is involved.
- ✓Pathology confirming NHL with immunohistochemistry results should be documented.
- ✓Disease stage, treatment approach (which may differ based on organ site), and response to therapy must be clearly recorded.