C85.2A
BillableMediastinal (thymic) large B-cell lymphoma, in remission
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C85.2A an HCC code?
Yes. C85.2A 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 C85.2A
For C85.2Ato 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 C85.2A during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C85.2A is the ICD-10-CM diagnosis code for mediastinal (thymic) large b-cell lymphoma, in remission. A type of chest cancer (mediastinal large B-cell lymphoma) that is currently in remission, meaning the cancer is responding to treatment or has resolved. C85.2A 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, C85.2A 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, C85.2A 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.
The '2A' suffix indicates remission status; ensure clinical documentation explicitly states remission before assigning this code. Because C85.2A 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 C85.2A sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •The '2A' suffix indicates remission status; ensure clinical documentation explicitly states remission before assigning this code
- •This code should replace active disease codes once remission is documented
Clinical Significance
Primary mediastinal large B-cell lymphoma in remission reflects a patient who has responded to treatment for this aggressive thymic-origin lymphoma. This subtype predominantly affects young adults (especially women) and has a favorable cure rate with R-CHOP or dose-adjusted R-EPOCH regimens. Remission documentation supports ongoing surveillance for the approximately 10-20% of patients who relapse.
Documentation Requirements
- ✓Provider documentation explicitly stating 'remission' or 'complete response' based on imaging (typically end-of-treatment PET/CT)
- ✓Original pathology confirming primary mediastinal (thymic) large B-cell lymphoma subtype
- ✓Date of remission achievement and method of response assessment
- ✓Surveillance plan with scheduled follow-up imaging and laboratory monitoring
Commonly Confused Codes
- •C85.1A (Unspecified B-cell lymphoma, in remission) — Use C85.2A when the specific subtype is confirmed as mediastinal/thymic large B-cell
- •C83.3A (Diffuse large B-cell lymphoma, in remission) — PMBCL is distinct from DLBCL and has its own code series
- •Z85.79 (Personal history of other malignant neoplasms of lymphoid tissue) — Use for fully resolved cancer with no monitoring; remission implies ongoing surveillance