2026 ICD-10-CM Diagnosis Code M31.10Thrombotic microangiopathy, unspecified

ICD-10-CM Codes›M00–M99›M30-M36›M31

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

M31.10 is a billable ICD-10-CM diagnosis code for thrombotic microangiopathy, unspecified. 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 acute intravascular thrombotic microangiopathy. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Systemic lupus erythematosus and connective tissue disorders and Vasculitis.

Code Identity

ICD-10-CM Code
M31.10
Billable Status
Yes — Valid for Submission
Code Describes
Thrombotic microangiopathy, unspecified
Short Description
Thrombotic microangiopathy, unspecified
Same as the full description in the CMS dataset.
Parent Code
M31.1
Thrombotic microangiopathy

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM30-M36Systemic connective tissue disorders
CategoryM31Other necrotizing vasculopathies
This CodeM31.10Thrombotic microangiopathy, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acute intravascular thrombotic microangiopathy
  • Chronic thrombotic microangiopathy
  • Thrombotic microangiopathy

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

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

    • Microangiopathy(peripheral)
      • thrombotic

Clinical ClassificationClinical

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

CCSR MUS024
Systemic lupus erythematosus and connective tissue disorders
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR CIR037
Vasculitis
Default principal diagnosis: inpatient No · outpatient No

Code History & ChangesHistory

Replacement M31.10 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 M31.10Overview

Is M31.10 (Thrombotic microangiopathy) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report thrombotic microangiopathy, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M31.10 group to?

When thrombotic microangiopathy, unspecified 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.