2026 ICD-10-CM Diagnosis Code D59.31Infection-associated hemolytic-uremic syndrome
ICD-10-CM Codes›D50–D89›D55-D59›D59
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- Risk Adjusts — HCC 109
- Not Chronic
D59.31 is a billable ICD-10-CM diagnosis code for infection-associated hemolytic-uremic syndrome. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 791, 793, 811 through 812. As a secondary diagnosis, it counts as a major complication or comorbidity (MCC) and places an inpatient stay in the highest severity level of its MS-DRG family. It does not count, however, when the principal diagnosis is one of 110 closely related codes. Coders also document this condition as infection-related hemolytic uremic syndrome. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections and Hemolytic anemia.
For Medicare Advantage risk adjustment, D59.31 maps to CMS-HCC Category 109 (Acquired Hemolytic, Aplastic, and Sideroblastic Anemias) under the V28 model, adding a risk factor of about 1.144 for a community, non-dual, aged beneficiary in payment year 2026.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
D59.31 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2026.
Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Infection-related hemolytic uremic syndrome
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Shiga toxin-producing E. coli [STEC] related hemolytic uremic syndrome
- Typical hemolytic uremic syndrome
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
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
The “use additional code” indicates that a secondary code could be used to further specify the patient’s condition. This note is not mandatory and is only used if enough information is available to assign an additional code.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Syndrome See Also: Disease;
infection-associated D59.31
infection-associated D59.31
typical D59.31
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Code History & ChangesHistory
Replacement D59.31 replaces the following previously assigned code(s):
- D59.3 - Hemolytic-uremic syndrome
Questions About D59.31Overview
What is the ICD-10 code for infection-associated hemolytic-uremic syndrome?
The ICD-10-CM code for infection-associated hemolytic-uremic syndrome is D59.31 (sometimes written as D5931). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is D59.31 (Hemolytic-uremic syndrome) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report infection-associated hemolytic-uremic syndrome on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does D59.31 group to?
When infection-associated hemolytic-uremic syndrome is the principal diagnosis on an inpatient stay, it groups to MS-DRG 791, 793, 811, 812, with relative weights from 0.9182 to 4.1696 depending on complications. Higher weights mean higher Medicare reimbursement.
Is D59.31 a CC or MCC?
CMS lists D59.31 as an MCC (major complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it places the inpatient stay in the highest-weighted DRG of its severity family. It does not count when the principal diagnosis is one of the 110 closely related codes in its exclusion list.
What HCC is D59.31?
D59.31 (infection-associated hemolytic-uremic syndrome) maps to CMS-HCC Category 109 (Acquired Hemolytic, Aplastic, and Sideroblastic Anemias), commonly written as HCC 109, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2026. It mapped to HCC 46 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 96.
Does D59.31 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, D59.31 adds a risk adjustment factor of about 1.144 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.529 to 1.815 depending on the payment segment). HCC 109 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 109 category page.
