2026 ICD-10-CM Diagnosis Code E10.A2Type 1 diabetes mellitus, presymptomatic, Stage 2

ICD-10-CM CodesE00–E89E08-E13E10

ICD-10-CM E10.A2
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E10.A2 is a billable ICD-10-CM diagnosis code for type 1 diabetes mellitus, presymptomatic, Stage 2. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 637 through 639. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Diabetes mellitus without complication; and Diabetes mellitus, Type 1.

Code Identity

ICD-10-CM Code
E10.A2
Billable Status
Yes — Valid for Submission
Code Describes
Type 1 diabetes mellitus, presymptomatic, Stage 2
Short Description
Type 1 diabetes mellitus, presymptomatic, Stage 2
Same as the full description in the CMS dataset.
Parent Code
Type 1 diabetes mellitus, presymptomatic

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE08-E13Diabetes mellitus
CategoryE10Type 1 diabetes mellitus
This CodeE10.A2Type 1 diabetes mellitus, presymptomatic, Stage 2

Coding GuidelinesGuidance

The diabetes mellitus codes are combination codes that include the type of diabetes mellitus, the body system affected, and the complications affecting that body system. As many codes within a particular category as are necessary to describe all of the complications of the disease may be used. They should be sequenced based on the reason for a particular encounter. Assign as many codes from categories E08 - E13 as needed to identify all of the associated conditions that the patient has.

The age of a patient is not the sole determining factor, though most type 1 diabetics develop the condition before reaching puberty. For this reason type 1 diabetes mellitus is also referred to as juvenile diabetes.

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.

Tabular List NotesGuidance

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

Inclusion Terms

  • Confirmed islet autoimmunity with dysglycemia

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.

    • Autoimmunity, confirmed islet, with dysglycemia
    • Diabetes, diabetic(mellitus) (sugar)
      • type 1
        • presymptomatic
          • Stage 2

Clinical ClassificationClinical

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

CCSR END002
Diabetes mellitus without complication
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR END004
Diabetes mellitus, Type 1
Default principal diagnosis: inpatient No · outpatient No

Code History & ChangesHistory

Replacement E10.A2 replaces the following previously assigned code(s):

  • R73.03 - Prediabetes
FY 2025AddedAdded to the ICD-10-CM code setEffective October 1, 2024.
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About E10.A2Overview

Is E10.A2 (Type 1 diabetes mellitus, presymptomatic) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report type 1 diabetes mellitus, presymptomatic, Stage 2 on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does E10.A2 group to?

When type 1 diabetes mellitus, presymptomatic, Stage 2 is the principal diagnosis on an inpatient stay, it groups to MS-DRG 637, 638, 639, with relative weights from 0.6212 to 1.4367 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.