Endocrine and metabolic diseases have a wide range of conditions affecting millions of people, which makes it imperative to have an in-depth understanding of ICD-10-CM guidelines and concepts so that the correct ICD-10-CM code is assigned based on documentation.
The ICD-10-CM code range for Endocrine, nutritional and metabolic diseases E00-E89 is a medical classification list by the World Health Organization (WHO). This chapter includes guidelines for correct ICD-10-CM code assignment for Disorders of the thyroid gland, Diabetes mellitus, Other disorders of glucose regulation and pancreatic internal secretion, Disorders of other endocrine glands, Intraoperative complications of the endocrine system, Malnutrition, and Other nutritional deficiencies.
Due to an extended list of Endocrine, nutritional, and metabolic conditions, today we will be going over the concept for correct ICD-10-CM code assignment for diabetes with related conditions.
Many of the ICD-10-CM diabetes codes are combination codes that include the type of diabetes mellitus, body system affected, and the complications affecting that body system. The guidelines also include instructions to use additional codes to further define other related conditions and the use of insulin or other antidiabetic drugs.
In 2016 AHA Coding Clinic published a clarification that the sub-term “with” in the index should be interpreted as a link between diabetes and any condition indented under the word with. This means that we can assume a “cause and effect” relationship with diabetes and those diseases. An example is type 2 diabetes with kidney disease. The physician’s documentation does not need to specify that the patient’s diabetes is linked to their kidney disease. As coders, we can assume this relationship.
A common scenario we see in medical records are type 2 diabetic patients with neuropathy. Approximately 1/3 to ½ of patients with diabetes have peripheral neuropathy. Coding diabetic patients with neurological complications can be confusing. The key is to understand the disease process. When a diabetic patient develops peripheral neuropathy, damage to the peripheral nerves they experience symptoms of weakness, numbness, and pain in the hands and feet. This nerve damage can impact multiple nerves (polyneuropathy). When a physician states peripheral neuropathy due to diabetes it is understood as polyneuropathy which codes to E11.42. Mononeuropathy usually occurs when there is damage to a single nerve or nerve group. We see this in patients with carpal tunnel syndrome and Bell’s palsy.
A few examples of diabetes combination codes:
A patient with type 2 diabetes presents for evaluation burning and tingling in both feet. Provider’s final diagnosis is type 2 diabetes with peripheral neuropathy and prescribes Lyrica. The correct code assignment for this scenario is:
- E11.42 type 2 diabetes mellitus with diabetic polyneuropathy
A diabetic patient with chronic kidney disease, stage 4. The patient has type 2 diabetes and takes insulin daily. The correct code assignment for this scenario is:
- E11.22 type 2 diabetes mellitus with diabetic chronic kidney disease
- N18.4 chronic kidney disease stage 4
- Z79.4 long term (current) use of insulin
A patient with type 1 diabetes is seen for severe proliferative diabetic retinopathy with macular edema in both eyes. The correct ICD-10-CM coding is:
- E10.3513, Type 1 diabetes mellitus with severe proliferative diabetic retinopathy with macular edema.
When reporting diabetes in pregnancy, the coder must review the codes in chapter 15, "Pregnancy, childbirth and the puerperium (O00-O9A)," to obtain the correct code combination. There are also instructions to include a final character indicating the trimester of pregnancy of which the mother is in.
For example, a pregnant mother with type 1 diabetes who is G2, P1 and is 24 weeks gestation, presents for evaluation of her diabetes. The correct ICD-10-CM coding is:
- O24.012, Pre-existing diabetes mellitus, type 1, in pregnancy, second trimester
- Z3A.24, 26 weeks gestation of pregnancy
It is important to remember to read the entire note to ensure the physician’s documentation is clear as to whether conditions are related to diabetes and that there is no documentation indicated that diabetes is not the underlying cause of the other condition. When in doubt query the physician.