C86.41
BillableBlastic NK-cell lymphoma, in remission
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C86.41 an HCC code?
Yes. C86.41 maps to Lymphoma and Other 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 C86.41
For C86.41 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 C86.41 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C86.41 is the ICD-10-CM diagnosis code for blastic nk-cell lymphoma, in remission. This is a rare type of blood cancer involving natural killer cells that are in remission, meaning the cancer is responding to treatment and symptoms have improved. The 'blastic' designation indicates the cancer cells are immature forms. C86.41 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, C86.41 maps to Lymphoma and Other Cancers (HCC 19) with a community, non-dual, aged base RAF weight of 0.105. Under the older V24 model, C86.41 mapped to the same category but with a base RAF weight of 0.675 — V28 recalibrated weights across the entire model. 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.
Ensure documentation clearly states the remission status, as the 5th character '1' specifically indicates remission; other characters would indicate different disease states (active, not in remission, etc.). Because C86.41 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 C86.41 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Ensure documentation clearly states the remission status, as the 5th character '1' specifically indicates remission; other characters would indicate different disease states (active, not in remission, etc.)
- •This code requires a primary malignancy diagnosis and should be used with caution to verify it's not being confused with other NK-cell lymphomas; confirm the specific blastic variant is documented by the oncologist
Clinical Significance
Blastic NK-cell lymphoma in remission represents an uncommon but favorable treatment outcome in this typically aggressive malignancy. Remission is most often achieved through intensive chemotherapy regimens similar to acute leukemia protocols, sometimes followed by stem cell transplantation. Close surveillance is essential due to the high relapse rate, and ongoing monitoring of skin, blood counts, and bone marrow may be required.
Documentation Requirements
- ✓Remission must be explicitly stated by the treating oncologist with supporting evidence from skin examination, blood work, bone marrow biopsy, and imaging studies.
- ✓The original pathologic confirmation of blastic NK-cell lymphoma must be in the medical record.
- ✓Surveillance plan and any transplant-related care must be documented.
Commonly Confused Codes
- •C86.40 (blastic NK-cell lymphoma not in remission) indicates active disease.
- •Z85.79 (personal history of malignant neoplasm of lymphoid tissue) should only be used when disease is considered cured.
- •C91.01 (acute lymphoblastic leukemia in remission) is a different entity despite similar treatment approaches.