E13.21

HCC Category Mapping

What This Code Means

A secondary form of diabetes that has damaged the kidneys, affecting their ability to filter waste from the blood.

Coding Tips

• •Nephropathy indicates kidney damage; verify kidney function tests or urinalysis results are documented
• •Use E13.22 if chronic kidney disease stage is specified; use E13.21 for general diabetic nephropathy

Clinical Significance

E13.21 identifies diabetic nephropathy in patients with other specified (secondary) diabetes mellitus. Diabetic nephropathy represents progressive kidney damage caused by chronic hyperglycemia, manifesting as persistent albuminuria, declining glomerular filtration rate, and eventual progression toward end-stage renal disease if not aggressively managed.

Documentation Requirements

• ✓Documentation must establish the secondary diabetes type with its underlying cause and confirm the diagnosis of diabetic nephropathy.
• ✓Supporting evidence includes persistent proteinuria or albuminuria, elevated serum creatinine, or reduced estimated glomerular filtration rate.
• ✓The causal link between diabetes and kidney disease must be stated or clearly implied.

Commonly Confused Codes