What is the best ICD‑10 coding for a patient with diabetes and mixed hyperlipidemia?

ICD-10 Coding for Diabetes with Mixed Hyperlipidemia

For a patient with diabetes and mixed hyperlipidemia, use two separate ICD-10 codes: one from the E11.6x series for type 2 diabetes with specified complications (if applicable) or E11.9 for type 2 diabetes without complications, plus E78.2 for mixed hyperlipidemia.

Primary Diabetes Code Selection

• Type 2 diabetes without complications: Use E11.9 as the primary diabetes code when the patient has no documented diabetic complications 1
• Type 2 diabetes with complications: Select from the E11.6x series if the patient has documented diabetic complications such as:
  • E11.65 for diabetes with hyperglycemia
  • E11.69 for diabetes with other specified complication
  • E11.21 for diabetes with diabetic nephropathy
  • E11.36 for diabetes with diabetic cataract 1
• Type 1 diabetes: Use E10.x codes if the patient has type 1 diabetes instead of type 2 1

Secondary Hyperlipidemia Code

• Mixed hyperlipidemia: Add E78.2 as a secondary diagnosis code to capture the mixed hyperlipidemia component 2
• This code specifically identifies elevated cholesterol and triglycerides occurring together, which is the most common dyslipidemia pattern in diabetic patients 2

Clinical Context for Code Selection

• Mixed hyperlipidemia in diabetes typically presents with elevated triglycerides, elevated LDL cholesterol, and reduced HDL cholesterol 3, 2
• The presence of additional cardiovascular risk factors (hypertension, smoking, chronic kidney disease, albuminuria) should be coded separately with their own ICD-10 codes 3
• Document any atherosclerotic cardiovascular disease (ASCVD) with appropriate I25.x codes, as this significantly impacts treatment intensity 3, 4

Common Coding Pitfalls to Avoid

• Do not use the generic code E11.9 (type 2 diabetes without complications) if specific diabetic complications are documented—this results in undercoding and fails to capture disease severity 1
• Do not use E78.5 (hyperlipidemia, unspecified) when the lipid pattern is known—E78.2 more accurately describes mixed hyperlipidemia with both elevated cholesterol and triglycerides 2
• Do not forget to code associated conditions separately, such as hypertension (I10), chronic kidney disease (N18.x), or obesity (E66.x), as these affect risk stratification and treatment decisions 3

Documentation Requirements

• Ensure the medical record clearly documents both the diabetes diagnosis (type 1 vs type 2, controlled vs uncontrolled) and the specific lipid abnormalities (elevated LDL, elevated triglycerides, low HDL) to support accurate code assignment 1, 5
• Document current glycemic control status and any diabetic complications to justify the most specific diabetes code 1
• Record baseline lipid panel values (total cholesterol, LDL-C, HDL-C, triglycerides) at diagnosis to support the mixed hyperlipidemia diagnosis 3, 4