ICD-10 Code E10.A1 – Type 1 diabetes mellitus, presymptomatic, Stage 1 (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E10.A1 – Type 1 diabetes mellitus, presymptomatic, Stage 1
What it is
This code identifies stage 1 presymptomatic type 1 diabetes mellitus. It means you are documenting early autoimmune disease before classic diabetes symptoms appear.
Clinical signs
Clinical features vary; refer to documentation. Stage 1 is typically identified by islet autoimmunity with no overt hyperglycemia or classic diabetic symptoms.
When to use this code
Use this code when the record specifically documents presymptomatic stage 1 type 1 diabetes. It may appear in screening, surveillance, or specialist notes describing autoimmune diabetes before clinical onset. Do not infer the stage from family history alone.
Do not use for
Do not use this code for established type 1 diabetes, type 2 diabetes, or other diabetes types. If the chart does not clearly state stage 1 presymptomatic disease, check documentation.
Coding tip
Assign E10.A1 only when the provider explicitly documents presymptomatic stage 1 type 1 diabetes.