D76.1
BillableHemophagocytic lymphohistiocytosis
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is D76.1 an HCC code?
Yes. D76.1 maps to Disorders of Immunity, Neutropenia under the CMS-HCC V28 risk adjustment model (and Disorders of Immunity 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 D76.1
For D76.1to 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 D76.1 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
D76.1 is the ICD-10-CM diagnosis code for hemophagocytic lymphohistiocytosis. A rare, serious condition where immune cells abnormally attack and destroy blood cells and other tissues throughout the body. D76.1 sits in the ICD-10-CM chapter for diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (d50-d89), within the section covering other disorders of blood and blood-forming organs (d70-d77).
Under the CMS-HCC V28 risk adjustment model, D76.1 maps to Disorders of Immunity, Neutropenia (HCC 115) with a community, non-dual, aged base RAF weight of 0.369. Under the older CMS-HCC V24 model, D76.1 maps to Disorders of Immunity (HCC 47) with a community, non-dual, aged base RAF weight of 0.472. 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 a life-threatening condition requiring urgent treatment; ensure accurate diagnosis documentation. Because D76.1 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 D76.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is a life-threatening condition requiring urgent treatment; ensure accurate diagnosis documentation
- •Distinguish between primary and secondary hemophagocytic lymphohistiocytosis if documented
Clinical Significance
Hemophagocytic lymphohistiocytosis is a life-threatening hyperinflammatory syndrome where activated macrophages and lymphocytes uncontrollably engulf blood cells, platelets, and other cellular components. This condition can be primary (genetic) or secondary (triggered by infection, malignancy, or autoimmune disease) and carries extremely high mortality without prompt immunosuppressive treatment.
Documentation Requirements
- ✓Documentation should include the diagnostic criteria met (fever, splenomegaly, cytopenias, hyperferritinemia, hypertriglyceridemia, elevated soluble interleukin-2 receptor, low natural killer cell activity, hemophagocytosis on biopsy).
- ✓Specify whether primary (familial) or secondary, underlying triggers, bone marrow biopsy findings if performed, ferritin levels, and treatment with immunosuppressive protocols.
Commonly Confused Codes
- •D76.2 (hemophagocytic syndrome, infection-associated, used when a specific infection is the documented trigger), D76.3 (other histiocytosis syndromes, used for non-hemophagocytic histiocytic disorders), C96.0 (multifocal Langerhans-cell histiocytosis, a neoplastic histiocyte disorder), D89.9 (unspecified immune disorder, far less specific).