ICD-10 Codes That Meet Medical Necessity for Hemoglobin A1c Testing
The primary ICD-10 codes that meet medical necessity for Hemoglobin A1c testing include diabetes diagnoses (E08-E13), prediabetes (R73.03), and specific risk factors outlined in diabetes screening guidelines. 1
Diabetes Diagnosis Codes
- E08.XX: Diabetes mellitus due to underlying condition
- E09.XX: Drug or chemical induced diabetes mellitus
- E10.XX: Type 1 diabetes mellitus
- E11.XX: Type 2 diabetes mellitus
- E13.XX: Other specified diabetes mellitus
Prediabetes and Screening Codes
- R73.03: Prediabetes
- R73.01: Impaired fasting glucose
- R73.02: Impaired glucose tolerance test
Risk Factor Codes for Screening
According to the American Diabetes Association guidelines, the following risk factor codes support medical necessity for A1c testing in asymptomatic individuals 1:
- E66.XX: Overweight and obesity (BMI ≥25 kg/m² or ≥23 kg/m² in Asian Americans)
- I10: Essential hypertension (≥130/80 mmHg or on therapy)
- E78.5: Dyslipidemia
- E78.00-E78.01: Hypercholesterolemia
- E78.1: Hypertriglyceridemia (>250 mg/dL)
- E78.2: Mixed hyperlipidemia
- E78.3: Hyperchylomicronemia
- E78.4: Other hyperlipidemia
- E28.2: Polycystic ovarian syndrome
- Z82.3: Family history of diabetes
- Z83.3: Family history of other endocrine disorders
- Z57.0: Occupational exposure to risk factors (physical inactivity)
- K76.0: Fatty liver disease not elsewhere classified
- Z91.89: Other specified personal risk factors (history of cardiovascular disease)
Gestational Diabetes Codes
- O24.XX: Diabetes mellitus in pregnancy
- Z86.32: Personal history of gestational diabetes
Testing Frequency Considerations
The appropriate testing frequency depends on clinical circumstances 1:
- Diagnosed diabetes with stable control: A1c testing twice yearly (every 6 months)
- Diagnosed diabetes with therapy changes or not meeting goals: Quarterly testing
- Prediabetes: Annual testing
- Normal screening results: Testing every 3 years
- Pregnancy with pre-existing diabetes: More frequent testing may be required
Special Considerations
Hemoglobinopathies and Anemias
In patients with conditions affecting red blood cell turnover or hemoglobin variants, A1c results may be inaccurate 1, 2. Alternative testing methods should be used:
- D50-D53: Nutritional anemias
- D55-D59: Hemolytic anemias
- D56.X: Thalassemias
- D57.X: Sickle-cell disorders
Pregnancy
During pregnancy, especially second and third trimesters, only blood glucose criteria should be used for diagnosis due to increased red cell turnover 1.
Clinical Pitfalls to Avoid
Inappropriate frequency: Testing more frequently than quarterly provides limited additional information as A1c reflects average glycemia over approximately 3 months 1.
Relying solely on A1c in certain conditions: In patients with hemoglobinopathies, recent blood loss, transfusion, erythropoietin therapy, or hemolysis, A1c may be inaccurate 1, 2.
Using point-of-care A1c for diagnosis: While point-of-care testing is useful for monitoring, it is not recommended for diagnostic purposes due to potential accuracy limitations 1.
Improper sample collection: HbA1c testing requires proper collection in EDTA tubes; improper collection or tube transfer can compromise sample integrity 3.
By ensuring appropriate ICD-10 coding that aligns with these medical necessity criteria, providers can facilitate proper reimbursement while ensuring patients receive clinically indicated A1c testing.