D75.822
BillableImmune-mediated heparin-induced thrombocytopenia
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is D75.822 an HCC code?
Yes. D75.822 maps to Coagulation Defects and Other Specified Hematological Disorders under the V24 model but is not retained in V28.
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 D75.822
For D75.822to 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 D75.822 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
D75.822 is the ICD-10-CM diagnosis code for immune-mediated heparin-induced thrombocytopenia. An immune system reaction to heparin medication that causes a severe drop in platelet count and increased risk of blood clots. D75.822 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 older CMS-HCC V24 model, D75.822 maps to Coagulation Defects and Other Specified Hematological Disorders (HCC 48) with a community, non-dual, aged base RAF weight of 0.192. 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 the more common form of HIT; ensure immune mechanism is documented before coding this instead of D75.821. Because D75.822 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 D75.822 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is the more common form of HIT; ensure immune mechanism is documented before coding this instead of D75.821
- •Document any thrombotic complications that may have occurred as a result of immune HIT
Clinical Significance
Immune-mediated heparin-induced thrombocytopenia (HIT Type II) is a serious prothrombotic condition caused by antibodies against platelet factor 4-heparin complexes. Despite causing thrombocytopenia, HIT paradoxically increases thrombotic risk, with up to 50% of untreated patients developing arterial or venous thrombosis. Immediate heparin cessation and initiation of alternative anticoagulation (argatroban, bivalirudin, fondaparinux) is mandatory.
Documentation Requirements
- ✓Document platelet count decline of >50% from baseline occurring 5-10 days after heparin exposure (or within 1 day if prior heparin exposure within 100 days), positive HIT antibody testing (PF4-ELISA and/or serotonin release assay), and 4Ts score.
- ✓Record all heparin products discontinued (including flushes), alternative anticoagulant initiated, and any thrombotic complications.