If the documentation in a medical record does not indicate the type of diabetes but does indicate the patient uses insulin, type 2 must be reported. Some patients with type 2 diabetes mellitus are unable to control their blood sugar through diet/exercise and oral medication alone, and require insulin. The use of insulin does not mean a patient is a type 1 diabetic. All type 1 diabetics must use insulin to replace what their bodies do not produce. If the type of diabetes mellitus is not documented in the medical record, the default is type 2. The 4th character under these categories refers to underlying conditions with specified complications, whereas, the 5th character defines the specific manifestation such as neuropathy, angiopathy, etc. They are: -E08 Diabetes mellitus due to an underlying condition -E09 Drug or chemical induced diabetes mellitus -E10 Type 1 diabetes mellitus -E11 Type 2 diabetes mellitus -E13 Other specified diabetes mellitus All the categories above with the exception of E10 include a note directing users to use an additional code to identify any insulin use (Z79.4) or use of oral antidiabetic or oral hypoglycemic drugs (Z79.84). Diabetes mellitus codes in ICD-10-CM are combination codes that include: -Type of diabetes mellitus -Body system affected -The complications affecting that body system There are five diabetes mellitus categories in ICD-10-CM. Type 2 diabetics still produce insulin, but because of obesity, age, or genetic weakness, the insulin produced is not enough to keep their blood sugar levels within normal limits. This type of diabetes usually occurs early in life, typically in childhood or before the patient reaches the age of 30.

A Type 1 diabetic requires insulin to survive. There are two types of diabetes: Type 1 and Type 2. ICD-10-CM provides combination codes to report diabetes with manifestations. Diabetes mellitus (DM) is a complicated disease to code because of the different types of diabetes and the variety of diseases that manifest because of DM. Diabetes mellitus is one of the most frequently used category codes in chapter 4.

Breaking the diabetes code