Screen and Test for Prediabetes

Because there are no clear symptoms of prediabetes, screening and testing are an especially important part of prevention. Screening for prediabetes will enable healthcare professionals to either identify adults with prediabetes who could benefit from diabetes prevention lifestyle change programs or identify adults with undiagnosed diabetes who may require care to prevent the serious health complications of diabetes.

This page includes information about diabetes screening recommendations, the blood tests for prediabetes, and coverage for screening and testing for prediabetes. 


Diabetes Screening Recommendations

The US Preventive Services Task Force (USPSTF) diabetes screening guidelines recommends screening for abnormal blood glucose as part of cardiovascular risk assessment in adults aged 40 to 70 years who are overweight or obese.

In addition to the USPSTF diabetes screening guidelines, patients at risk for prediabetes may warrant screening based on family history, comorbid conditions, or individual risk factors such as race, ethnicity, and previous gestational diabetes. Screening for undiagnosed type 2 diabetes can help prevent or reduce small blood vessel complications (such as blindness, kidney failure, or amputations) and cardiovascular disease.

USPSTF diabetes screening guidelines recommend that patients with abnormal glucose, either prediabetes or diabetes, be offered intensive lifestyle change programs, such as the CDC-recognized DPP lifestyle change program.



The three types of blood tests that are commonly used to diagnose diabetes and prediabetes are the A1c test, fasting blood glucose test, and the oral glucose tolerance test. For a helpful diagram, see the Decision Pathway for Diabetes and Prediabetes from the National Institute of Diabetes and Digestive and Kidney Diseases. 

A1c Test

The A1c is a blood test results show what a person’s average blood sugar has been for the past two to three months. A normal range of blood sugar is less than 5.7%.

Normal: Less than 5.7%

Prediabetes: 5.7%-6.4%

Diabetes: Equal to or greater than 6.5%


Fasting Plasma Glucose Level Blood Test

The fasting plasma glucose level test measures blood sugar in a person who has been fasting (not eating) for at least eight hours. This is the most common test used to diagnose type 2 diabetes. 

Normal: Less than 100 mg/dL

Prediabetes: 100 to 125 mg/dL

Diabetes: Greater than 125 mg/dL


Oral Glucose Tolerance Test (2-hour Post-Glucose Challenge)

This test is done two hours after a person fasts (for at least eight hours) and then drinks a beverage containing sugar. This test is also used to diagnose gestational diabetes (diabetes during pregnancy).

Normal: Less than 140 mg/dL

Prediabetes (impaired glucose tolerance): 140 to 199 mg/dL

Diabetes: Equal to or greater than 200 mg/dL


See the table below from the US Preventive Services Task Force Diabetes Screening Guidelines for more information about the test values for normal glucose metabolism, impaired glucose tolerance (prediabetes), and type 2 diabetes. 


Three types of blood tests,  image from US Preventive Task Force



As of January 2017, private health plans are required to cover (at no cost to the patient):

  • Screening for prediabetes and diabetes, and
  • Participation in intensive behavioral counseling interventions such as the Diabetes Prevention Program (DPP) lifestyle change program for individuals screened and determined to have prediabetes.

Depending on the type of office visit, practices can use several CPT and ICD codes to bill for prediabetes screening and counseling. For a list of commonly used codes for screening prediabetes and diabetes please visit the Prevent Diabetes STAT Toolkit. Also, review the National Diabetes Prevention Program Coverage Toolkit from National Association of Chronic Disease Directors for more information about coverage for diabetes prevention lifestyle change programs.



Codes for Screening Prediabetes and Diabetes

Codes for Screening Prediabetes and Diabetes

The list of commonly used current procedural terminology and ICD codes from the Prevent Diabetes STAT Toolkit can be used for healthcare professionals to obtain reimbursement for prediabetes screening.

National Diabetes Prevention Program Coverage Toolkit

Review the National Diabetes Prevention Program Coverage Toolkit from the National Association of Chronic Disease Directors to learn about coverage for the CDC-recognized Diabetes Prevention Program lifestyle change program. 

Coverage Toolkit
Decision Pathway for Identifying Adults with Diabetes and Prediabetes

Decision Pathway for Identifying Prediabetes

Using the patient's blood test results, consult the diagram from the National Institute of Diabetes and Digestive and Kidney Diseases to help decide next steps for the patient. 

Information and materials in the "Healthcare Professionals" section of this website may be adapted and/or sourced from the Prevent Diabetes STAT Toolkit, a guide developed by the American Medical Association and the Centers for Disease Control and Prevention. The Prevent Diabetes STAT Toolkit helps healthcare teams "screen, test, and act today" by referring patients to a Diabetes Prevention Program lifestyle change program.