Type 1 diabetes is classified under ICD-10-CM code E10, which requires specifying the complication. Common billable codes include E10.10 (ketoacidosis without coma), E10.11 (ketoacidosis with coma), E10.65 (hyperglycemia), and E10.9 (without complications).
Primary codes
Billable
Billable
Extension
—
7th character
—
POA exempt
No
Coding risks
- Incorrectly coding when complications are present but not documented
Hierarchy
Code comparison
Compare key differences between related codes to select the most specific option.
| Code | Description | Scenario |
|---|---|---|
| E10.9 | Type 1 diabetes mellitus without complications | T1DM documented with no ketoacidosis, hyperglycemia, coma, or other complications noted. |
| E10.10 | Type 1 diabetes mellitus with ketoacidosis without coma | T1DM with documented diabetic ketoacidosis, patient alert without coma or loss of consciousness. |
| E10.11 | Type 1 diabetes mellitus with ketoacidosis with coma | T1DM with diabetic ketoacidosis and documented coma at presentation. |
| E10.65 | Type 1 diabetes mellitus with hyperglycemia | T1DM with documented hyperglycemia, no ketoacidosis or coma noted. |
Select the most specific code supported by the encounter documentation. More specific codes improve reimbursement accuracy and reduce audit risk.
Code ranges
Type 1 diabetes mellitus
Codes capture type 1 diabetes by complication, covering ketoacidosis, kidney, ophthalmic, neurological, circulatory, and other specified or unspecified manifestations.
Diabetes mellitus
Parent block grouping all diabetes mellitus categories by etiology, including secondary, drug-induced, type 1, type 2, and other specified forms.
Type 2 diabetes mellitus
Codes capture type 2 diabetes by complication, including hyperosmolarity, ketoacidosis, kidney, ophthalmic, neurological, circulatory, and other specified manifestations.
Diabetes mellitus in pregnancy, childbirth, and the puerperium
Codes classify pre-existing and gestational diabetes during pregnancy, delivery, and the postpartum period by type and trimester.
Other specified diabetes mellitus
Codes capture diabetes due to genetic defects, postpancreatectomy, postprocedural, or other specified causes not classified elsewhere.
Coding risks
Avoid these common coding issues when reporting Type 1 Diabetes.
Impact
Assigning E10 without explicit type may miscode as type 2 diabetes (E11), the default for unspecified DM.
Mitigation
Consider querying the provider when type is absent rather than inferring from age, insulin use, or onset history.
Related codes
Ancillary and co-coding
Codes commonly reported with the primary diagnosis on the same claim.
Z-code variants
Family history, personal history, or screening encounter codes related to this condition.
In pregnancy
Pregnancy-specific O-code adaptations used in place of the primary when the condition occurs during or complicates pregnancy.
Differential codes
Alternative or commonly confused codes to consider when documentation suggests a different condition than the primary diagnosis.
Frequently asked questions
No. Per ICD-10-CM guidelines, Z79.4 is not assigned with type 1 diabetes since insulin use is inherent to the diagnosis.
References
Compiled from the following authoritative coding references. Last updated 2026-05-15.