D75.829
BillableHeparin-induced thrombocytopenia, unspecified
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is D75.829 an HCC code?
Yes. D75.829 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 D75.829
For D75.829 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 D75.829 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
D75.829 is the ICD-10-CM diagnosis code for heparin-induced thrombocytopenia, unspecified. A drop in platelet count caused by heparin medication when the specific type or mechanism is not specified or documented. D75.829 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, D75.829 maps to Coagulation Defects and Other Specified Hematological Disorders (HCC 48) with a community, non-dual, aged base RAF weight of 0.209. 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 default code; attempt to determine immune vs. non-immune status from clinical documentation before using this unspecified code. Because D75.829 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 D75.829 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is a default code; attempt to determine immune vs. non-immune status from clinical documentation before using this unspecified code
- •Query the provider if the type of HIT is not clearly documented
Clinical Significance
Heparin-induced thrombocytopenia, unspecified, indicates a documented drop in platelet count caused by heparin exposure where the provider has not specified whether it is immune-mediated (type II) or non-immune (type I). Both types have significantly different clinical implications, with type II carrying life-threatening thrombotic risk.
Documentation Requirements
- ✓Documentation should include the temporal relationship between heparin administration and platelet decline, nadir platelet count, percentage of platelet drop from baseline, and any thrombotic complications.
- ✓Providers should be queried to specify immune vs.
- ✓non-immune type, as this significantly impacts treatment decisions and coding specificity.
- ✓Include anti-PF4 antibody testing results if performed.
Commonly Confused Codes
- •D75.821 (immune-mediated heparin-induced thrombocytopenia, preferred when anti-PF4 antibodies are positive), D75.822 (non-immune heparin-induced thrombocytopenia, preferred for mild transient type I), D75.828 (other specified heparin-induced thrombocytopenia for atypical variants), D69.59 (other secondary thrombocytopenia from non-heparin causes).