2026 ICD-10-CM Diagnosis Code M31.11Hematopoietic stem cell transplantation-associated thrombotic microangiopathy [HSCT-TMA]

ICD-10-CM CodesM00–M99M30-M36M31

ICD-10-CM M31.11
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M31.11 is a billable ICD-10-CM diagnosis code for hematopoietic stem cell transplantation-associated thrombotic microangiopathy [HSCT-TMA]. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 545 through 547. Coders also document this condition as thrombotic microangiopathy following transplantation of hematopoietic stem cell. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Complication of transplanted organs or tissue, initial encounter; Systemic lupus erythematosus and connective tissue disorders; and Vasculitis.

Code Identity

ICD-10-CM Code
M31.11
Billable Status
Yes — Valid for Submission
Code Describes
Hematopoietic stem cell transplantation-associated thrombotic microangiopathy [HSCT-TMA]
Short Description
Hematpoetc stem cell txpltation-assoc throm microangiopathy
Parent Code
Thrombotic microangiopathy

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM30-M36Systemic connective tissue disorders
CategoryM31Other necrotizing vasculopathies
This CodeM31.11Hematopoietic stem cell transplantation-associated thrombotic microangiopathy [HSCT-TMA]

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Thrombotic microangiopathy following transplantation of hematopoietic stem cell

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Transplant-associated thrombotic microangiopathy TA-TMA

Code First

  • if applicable:
  • complications of bone marrow transplant T86.0
  • complications of stem cell transplant T86.5

Use Additional Code

  • code to identify specific organ dysfunction, such as:
  • acute kidney failure N17
  • acute respiratory distress syndrome J80
  • capillary leak syndrome I78.8
  • diffuse alveolar hemorrhage R04.89
  • encephalopathy metabolic septic G93.41
  • fluid overload, unspecified E87.70
  • graft versus host disease D89.81
  • hemolytic uremic syndrome D59.3
  • hepatic failure K72
  • hepatic veno-occlusive disease K76.5
  • idiopathic interstitial pneumonia J84.11
  • sinusoidal obstruction syndrome K76.5

Index to Diseases and InjuriesGuidance

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • HSCT-TMA(hematopoietic stem cell transplantation-associated thrombotic microangiopathy)
    • Microangiopathy(peripheral)
      • thrombotic
        • hematopoietic stem cell transplantation-associated [HSCT-TMA]

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ036
Complication of transplanted organs or tissue, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR MUS024
Systemic lupus erythematosus and connective tissue disorders
Default principal diagnosis: inpatient No · outpatient No
CCSR CIR037
Vasculitis
Default principal diagnosis: inpatient No · outpatient No

Code History & ChangesHistory

Replacement M31.11 replaces the following previously assigned code(s):

  • M31.1 - Thrombotic microangiopathy
FY 2022AddedAdded to the ICD-10-CM code setEffective October 1, 2021.
FY 2023–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About M31.11Overview

Is M31.11 (Thrombotic microangiopathy) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report hematopoietic stem cell transplantation-associated thrombotic microangiopathy [HSCT-TMA] on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M31.11 group to?

When hematopoietic stem cell transplantation-associated thrombotic microangiopathy [HSCT-TMA] is the principal diagnosis on an inpatient stay, it groups to MS-DRG 545, 546, 547, with relative weights from 0.8362 to 2.4817 depending on complications. Higher weights mean higher Medicare reimbursement.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.