Introduction

The American Diabetes Association's (ADA's) Standards of Care in Diabetes–2024 recommends consistent use of continuous glucose monitoring (CGM) for people who have type 1 or type 2 diabetes and take insulin.¹ This includes any insulin regimen, whether basal insulin only, multiple daily administrations of insulin, or an insulin pump.

The American Academy of Family Physicians (AAFP) has numerous resources to assist with implementing, prescribing, and interpreting data from and supporting the use of CGM in practice. These include a dedicated webpage, physician-facing and patient-facing handouts and education resources, brief videos, insurance navigation and coverage aids, information on professional CGM, tips on billing and coding for CGM services, practice implementation assistance, and continuing education. This supplement will review some of these resources and where to access them.

How Can CGM be Helpful in Diabetes Management?

Using CGM in diabetes management has been shown to decrease A1C, even in the absence of other interventions.¹ Patients describe the benefits of knowing their glucose level in real time and seeing how eating certain foods does or does not affect it. CGM can also provide much deeper insight into glucose patterns than a single value such as an A1C level, which is only an average. Having information about how much time a patient's glucose level is within, above, and below the target glucose range makes it easier to identify and act upon patterns. Increased time in range is also associated with improved outcomes, including reduced risk of long-term complications.^1,2

In light of how dangerous hypoglycemia can be and how often people experiencing it are asymptomatic, CGM can be especially helpful for identifying hypoglycemia.² CGM systems can also alert patients and/or their caregivers to predicted low glucose levels so they can intervene early to prevent hypoglycemia altogether or minimize its severity and/or duration.

In addition, CGM data can be useful to calculate a patient's glucose management indicator (GMI), an estimate of A1C based on their average CGM glucose level.³ This can provide an opportunity to make changes sooner than the next A1C reading and could help with both patient- and provider-level therapeutic inertia, which are common.⁴ CGM can also be used to determine the true average glucose level of patients for whom A1C is known to be inaccurate, such as patients who are pregnant, patients who have hemoglobinopathies such as thalassemia, or conditions such as anemia or chronic kidney disease.

First Stop: CGM Webpage: www.aafp.org/CGM

Many resources highlighted in this supplement are on this central, CGM-focused AAFP webpage. Explore the page, bookmark it, and check back from time to time—the CGM landscape can change fairly frequently, and this webpage will be updated periodically.

Getting Started With CGM

The AAFP has patient education handouts providing an overview of CGM. They are available in English and Spanish. There is a thorough patient education article on the AAFP's patient-facing website (familydoctor.org) called "Monitoring Your Blood Sugar Level."  The webpage contains information on finger-stick glucose monitoring and CGM, as well as brief videos at the bottom about patient experiences, a demo of a CGM device, and understanding CGM data.

The AAFP's physician-facing webpage includes videos on CGM in your practice with information about being inclusive, identifying implicit bias, and shared decision-making with patients.

FPM has amassed helpful articles, educational supplements, and blog posts about CGM, including topics such as implementing CGM in practice, updates about Medicare coverage for CGM, adding CGM to your practice, and streamlining CGM workflow.

Comprehensive Resource for Implementing CGM in Practice

The AAFP TIPS^TM resource “Continuous Glucose Monitoring (CGM): Enhancing Diabetes Care, Workflows, Education, and Payment” has recently been updated to reflect changes in CGM practice. This resource offers a CME-accredited course for at least one interested diabetes or CGM champion in a practice, plus numerous tools for every step in the process and customizing the process to fit your practice's specific structure, patients, and needs. The first version, launched in 2021, was the most popular AAFP TIPS^TM resource ever. The updated module includes resources for your entire practice, including information about step-by-step implementation; case studies; insurance coverage guidance; prescribing/ordering devices; and documentation, billing, and coding, as well as other best practice tools.

Insurance Coverage and Ordering

The most-requested information by family physicians interested in starting patients on CGM is about CGM training and understanding and navigating insurance coverage,⁵ which you can find on the AAFP's “CGM Care Resources” webpage. For insurance guidance, scroll to the header, ‘What Type of Coverage Does the Patient Have?’ and you'll find information about coverage requirements and guidance for Medicare, Medicaid, and private payers (please note the tabs for different payer types). You'll also find details about ordering CGM devices and providing supporting documentation in that section, including example documentation to include in your patient notes and even the ability to copy that documentation and create macros you can save to your electronic health record. This resource can help your practice set and maintain patient expectations throughout the coverage approval process, including when your patients might expect to receive their CGM device and who they should contact for updates. These CGM postcards can be printed and distributed to patients with contact information for their CGM device prescription.

Medicare Coverage for CGM

Medicare now covers CGM for all people with diabetes on insulin (even basal only) or with problematic hypoglycemia. Medicare has updated its coverage of CGM a few times in the past few years, most recently in April 2023.⁵ As noted previously in this supplement, for the 2023 updates, FPM recently published an educational supplement devoted to updates about Medicare coverage for CGM, including recent Medicare coverage criteria and changes, a flowchart to determine eligibility, and key steps for prescribing CGM for Medicare beneficiaries.

Professional CGM in Practice

Professional CGM systems are purchased and owned by practices, as opposed to personal CGM devices, which are prescribed and ordered for patients and then owned by the patient. Professional CGM systems can be beneficial in many circumstances. A professional CGM system is likely a viable option if a patient seems unlikely to qualify for a personal CGM device based on their insurer's criteria. Professional CGM systems are a popular way for practices to start with CGM for their patients. Similar to personal CGM devices, professional CGM systems offer an additional revenue opportunity (beyond evaluation and management), which few other services do in primary care. The AAFP's information about professional CGM systems explains their advantages (including a video), discusses how and where to purchase a professional CGM system, and includes several important sections covering how to: document your recommendation to use one, describe and demonstrate the application of one, get the data from one, and bill for one.

What Potential Challenges Are Involved in Prescribing CGM?

The insurance authorization process is the most prevalent barrier to implementing CGM effectively.⁶ A confusing aspect of this process is that some payers and/or plans require that CGM prescriptions be sent to a durable medical equipment (DME) supplier rather than a pharmacy (unless the pharmacy is also a DME supplier). Medicare plans are notable examples. If a prescription is sent to a pharmacy, the pharmacy may communicate to you or your patient that CGM is not covered. However, in many cases, the claim would have been approved if it had been processed as a DME benefit rather than a pharmacy benefit. If a pharmacy says CGM is not covered, try resending the prescription to a DME supplier instead. The reverse may also apply: if you send it to a DME supplier first and it is not covered, try sending it to a pharmacy instead.

Some patients prescribed CGM find it challenging to create an online user account and connect their CGM device to their account. Your patients may reach out to your practice for help. If you can help, that is great. Manufacturers of CGM systems also offer patient education materials to assist with this process, including instruction sheets and brief online videos.

Closing Thoughts

CGM has become a very popular option with patients and has become the standard of care for many patients with diabetes, according to numerous societies (including the ADA), and its indications and applications continue to mount. The landscape rapidly changes as new devices become available and insurance coverage expands. With this in mind, many more patients stand to benefit from the use of CGM and are likely to ask you about it. You can position your practice and your patients to enjoy the benefits of CGM by becoming familiar with it and using the numerous resources the AAFP has available to help.

This supplement was supported by an educational grant to the AAFP from Abbott Diabetes Care.