D59.13
BillableMixed type autoimmune hemolytic anemia
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is D59.13 an HCC code?
Yes. D59.13 maps to Hemolytic and Aplastic Anemias under the CMS-HCC V28 risk adjustment model (and Severe Hematological Disorders 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 D59.13
For D59.13 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 D59.13 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
D59.13 is the ICD-10-CM diagnosis code for mixed type autoimmune hemolytic anemia. Anemia caused by antibodies that attack red blood cells both at normal body temperature and in cold conditions, combining features of both warm and cold types. D59.13 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 hemolytic anemias (d55-d59).
Under the CMS-HCC V28 risk adjustment model, D59.13 maps to Hemolytic and Aplastic Anemias (HCC 109) with a community, non-dual, aged base RAF weight of 0.291. Under the older CMS-HCC V24 model, D59.13 maps to Severe Hematological Disorders (HCC 46) with a community, non-dual, aged base RAF weight of 0.666. 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.
Confirm both warm and cold reactive antibodies are documented in laboratory results. Because D59.13 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 D59.13 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Confirm both warm and cold reactive antibodies are documented in laboratory results
- •This is a less common type; ensure clear documentation supports this diagnosis
Clinical Significance
Mixed type autoimmune hemolytic anemia is a rare condition where patients produce both warm-reactive immunoglobulin G antibodies and cold-reactive immunoglobulin M antibodies that simultaneously attack red blood cells. This dual antibody pattern creates a particularly challenging clinical scenario because treatment must address both antibody types, and the condition often resists standard monotherapy approaches. Mixed type disease frequently occurs secondary to systemic lupus erythematosus or lymphoproliferative disorders and may indicate more severe underlying autoimmune dysregulation.
Documentation Requirements
- ✓Document laboratory evidence of both warm (immunoglobulin G) and cold (immunoglobulin M) antibodies on direct antiglobulin testing.
- ✓Record hemoglobin levels, hemolysis markers, and complement levels.
- ✓Document any underlying associated condition such as systemic lupus erythematosus or lymphoma.
- ✓Include cold agglutinin titers alongside warm antibody characterization.
- ✓Note treatment approach and response, as combination therapy may be required.
Commonly Confused Codes
- •D59.11 (Warm autoimmune hemolytic anemia) is used when only warm antibodies are present.
- •D59.12 (Cold autoimmune hemolytic anemia) applies when only cold antibodies are present.
- •D59.10 (Autoimmune hemolytic anemia, unspecified) should not be used when mixed type is confirmed by laboratory testing.
- •D59.19 (Other autoimmune hemolytic anemia) is for types that do not fit warm, cold, or mixed categories.