D59.31
BillableInfection-associated hemolytic-uremic syndrome
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is D59.31 an HCC code?
Yes. D59.31 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 D59.31
For D59.31 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 D59.31 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
D59.31 is the ICD-10-CM diagnosis code for infection-associated hemolytic-uremic syndrome. A serious condition where an infection triggers the destruction of red blood cells and kidney failure. D59.31 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, D59.31 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, D59.31 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.
Identify and code the causative infection separately (typically E. coli O157:H7 or other Shiga toxin-producing organisms). Because D59.31 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 D59.31 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Identify and code the causative infection separately (typically E. coli O157:H7 or other Shiga toxin-producing organisms)
- •Document the specific infectious agent when available to support medical necessity
Clinical Significance
Infection-associated hemolytic-uremic syndrome (typical hemolytic-uremic syndrome) is most commonly caused by Shiga toxin-producing Escherichia coli (particularly serotype O157:H7) and accounts for approximately 90% of all hemolytic-uremic syndrome cases, predominantly affecting children under age 5. The Shiga toxin damages endothelial cells in renal glomeruli, triggering the characteristic triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. Most cases are preceded by a prodromal bloody diarrheal illness 5-10 days before hemolytic-uremic syndrome onset.
Documentation Requirements
- ✓Document the causative infectious organism with culture or polymerase chain reaction results when available.
- ✓Record the prodromal illness (typically bloody diarrhea) with timeline to hemolytic-uremic syndrome onset.
- ✓Include laboratory values: creatinine, hemoglobin, platelet count, peripheral smear showing schistocytes, lactate dehydrogenase, and stool studies.
- ✓Document renal function status, any dialysis requirement, and complications such as seizures, pancreatitis, or colonic necrosis.
- ✓Code the infectious organism separately.
Use Additional Code
- code to identify associated infection, such as :
- E. coli infection (B96.2-)
- Human immunodeficiency virus [HIV] disease (B20)
- Pneumococcal meningitis (G00.1)
- Pneumococcal pneumonia (J13)
- Sepsis due to Streptococcus pneumoniae (A40.3)
- Shigella dysenteriae (A03.9)
- Streptococcus pneumoniae as the cause of diseases classified elsewhere (B95.3)
Commonly Confused Codes
- •D59.32 (Hereditary hemolytic-uremic syndrome) involves genetic complement pathway defects without infectious trigger.
- •D59.39 (Other hemolytic-uremic syndrome) covers non-infectious, non-hereditary causes.
- •D59.30 (Hemolytic-uremic syndrome, unspecified) should not be used when the infectious etiology is confirmed.
- •A04.7 (Enterocolitis due to Clostridium difficile) or B96.2x (Escherichia coli) may be needed as additional codes for the causative organism.