When to Query for Diabetes Mellitus with Complications

Diabetes Mellitus, also known as diabetes, is a chronic disease that occurs when the pancreas doesn’t produce enough insulin or when the body is unable to use insulin properly. 

The body’s inability to use insulin causes glucose to remain in the bloodstream rather than entering cells to be used for energy. Elevated blood glucose levels can lead to the development of complications in systems throughout the body.

Recognizing opportunities to query for clarification regarding a condition’s connection to diabetes requires understanding the signs and symptoms, clinical criteria and treatment that indicate a diagnosis of diabetes mellitus and the conditions that are commonly associated with having diabetes.

What is the Definition of Diabetes Mellitus?

The American Diabetes Association defines diabetes Mellitus as a group of metabolic diseases characterized by hyperglycemia (high blood sugar) resulting from defects in insulin secretion, insulin action or both. This chronic condition can lead to long term damage to organs, including eyes, kidneys, nerves, heart and blood vessels.

What is the Function of the Pancreas and How Does it Relate to Diabetes?

The pancreas has both an exocrine and endocrine role. The exocrine function involves production of digestive enzymes such as amylase and lipase which are released to aid digestion. The endocrine function secretes hormones like insulin and glucagon directly into the bloodstream to regulate blood sugar.

What are the Symptoms of Diabetes?

Symptoms of diabetes include:

• Frequent urination
• Frequent feeling of thirst
• Feeling hungry often
• Extreme fatigue
• Blurry vision
• Slow healing of cuts/bruises
• Involuntary weight loss
• Tingling, numbness or pain in the hands/feet

Pre Diabetes

Pre-diabetics may not have any signs/symptoms other than some people may have darkened patches of skin in the groin, armpit or neck area.

Gestational Diabetes

Often women have no symptoms but women should be screened during pregnancy. Most women are generally tested in the second trimester with a glucose tolerance test.

What are the Criteria for Diagnosing Diabetes?

A diagnosis of diabetes is based on the following criteria:

• HbA1C > 6.5
• Fasting blood sugar > 125mg
• 2-hour oral glucose tolerance test > 200 mg
• Random glucose level >200 + symptoms of hyperglycemia
• Diabetes hyperglycemia: blood sugar >140 mg
• Diabetes hypoglycemia: blood sugar <70 mg

How is Diabetes Treated?

The main treatments for diabetes include lifestyle changes and medication

• Managing diet and exercising
• Monitoring glucose (by device/finger stick)
• Hypoglycemic drugs
• Medication management
  • DPP-4 inhibitors
  • GLP-1 receptors
  • SGLT2 inhibitors
  • Sulfonylureas
  • Insulin

What are the Complications of Diabetes?

Many complications can develop as a result of having diabetes, including:

• Diabetic ketoacidosis
• Diabetic gastroparesis
• Diabetic hyperglycemia hyperosmolar (HHS)
• Coronary artery disease (CAD)
• Peripheral angiopathy
• Chronic kidney disease (CKD)
• Diabetes related eye disease (diabetic retinopathy)
• Neuropathy (nerve damage) (peripheral/autonomic)
• Chronic wounds/ulcers (often of the feet/legs)
• Skin conditions (cellulitis, dry/flaky skin)

Coding Challenges 

The need for accurate documentation and review of clinical information makes coding for complications of diabetes a challenge. Coders must be familiar, and up to date, with ICD-10-CM Official Guidelines for Coding and Reporting and AHA Coding Clinics to correctly assign codes for diabetes and its associated complications.

According to the ICD-10-CM “With” coding convention, all conditions listed in the Alphabetic Index under the main term Diabetes and the subterm with have a presumed causal relationship unless the physician has stated otherwise. Coding Clinic has further clarified that this presume linkage does not apply to NEC diagnoses. In these cases, the physician must establish a link/relationship between diabetes and the NEC diagnosis before combination codes for diabetic complications are assigned.

Example

Based on these entries in the ICD-10-CM Alphabetic Index there is a presumed link between diabetes and osteomyelitis unless stated otherwise, but a link between diabetes and cellulitis is not presumed and would require querying to link the two if a causal relationship is not documented by the physician.

Clear and detailed documentation from providers is essential for accurate code assignment. Coders may need to query providers for clarification on ambiguous or deficient documentation. 

How do you Know When to Query for Diabetes?

Conditions that are documented as having a possible link to diabetes may need a query to establish the relationship between diabetes and the condition, especially if the condition is being considered for the principal diagnosis, as reporting of the condition alone vs. as a diabetic complication may impact reimbursement.

Documentation of hyperglycemia that may be due to drug or insulin pump underdosing could be queried to clarify for the use of complication codes vs diabetes only codes.

If uncomplicated diabetes is documented in the record along with conditions such as CKD that have presumed linkage a query should be posed to ascertain if the two conditions should be linked or not.

Clinical validation queries may be required for diagnosis such as diabetic ketoacidosis, diabetic hyperglycemic hyperosmolar state or diabetic peripheral angiopathy with gangrene for example when their presence is not supported by clinical indicators as these have potential for impact on DRG.

References

• https://www.pinsonandtang.com
• https://diabetes.org
• https://www.cdc.gov/diabetes/about/index.html
• Coding Clinic for ICD-10-CM/PCS, First Quarter 2025, Page 35
• Coding Clinic for ICD-10-CM/PCS, Fourth Quarter 2017: Page 100
• Coding Clinic for ICD-10-CM/PCS, Fourth Quarter 2017: Page 101
• Coding Clinic for ICD-10-CM/PCS, Third Quarter 2024, Page 12

For more than 30 years, HIA has been the leading provider of compliance audits, coding support services and clinical documentation audit services for hospitals, ambulatory surgery centers, physician groups and other healthcare entities. HIA offers PRN support as well as total outsource support.

The information contained in this coding advice is valid at the time of posting. Viewers are encouraged to research subsequent official guidance in the areas associated with the topic as they can change rapidly.