ICD-10 Code E08.21 – Diabetes mellitus due to underlying condition with diabetic nephropathy (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E08.21 – Diabetes mellitus due to underlying condition with diabetic nephropathy
What it is
This code identifies diabetes that results from another underlying condition and is complicated by diabetic nephropathy. Use it when the record links the diabetes to the cause and documents kidney involvement.
Clinical signs
Clinical features vary; refer to documentation. Common findings in diabetic nephropathy include proteinuria, declining kidney function, and chronic kidney disease noted by the clinician.
When to use this code
Use E08.21 when the provider documents diabetes due to an underlying condition and specifically states diabetic nephropathy. You should code it from the current encounter record, not from assumptions.
If the note mentions diabetic kidney disease, nephropathy, or renal involvement tied to secondary diabetes, this code may apply. Check documentation for the underlying condition and any additional diabetes manifestations.
Do not use for
Do not use this code for type 1 or type 2 diabetes with nephropathy. Also avoid it if nephropathy is not documented or if the diabetes is not stated to be due to another condition.
Coding tip
Always verify the causal link between the underlying condition, diabetes, and nephropathy before assigning E08.21.