A Continuous Glucose Monitor (CGM) is a medical device that automatically tracks glucose levels throughout the day and night. This technology uses a small sensor inserted under the skin to measure interstitial fluid glucose, providing real-time data and trend arrows to improve management. Determining who qualifies for this tool involves meeting specific medical criteria and navigating established coverage standards.
Core Medical Eligibility Criteria
Qualification for a personal CGM device is primarily determined by a medical need to manage blood sugar variations that could lead to immediate health risks. The most direct path to eligibility is a confirmed diagnosis of diabetes mellitus coupled with a treatment regimen that involves insulin. This applies to individuals with Type 1 diabetes and many with Type 2 diabetes. Recent policy changes have expanded coverage to any patient treated with insulin, regardless of the dose or frequency.
Major payers have largely eliminated the original restriction requiring multiple daily injections or continuous pump use. This expansion recognizes the clinical benefit of CGM for individuals using even basal (long-acting) insulin to achieve better glycemic control. The device provides necessary insight into how different insulin doses affect glucose levels throughout the day and night.
A second path to qualification exists for individuals who experience frequent or problematic low blood sugar, known as hypoglycemia. This criterion applies even if diabetes is managed without insulin. Problematic hypoglycemia is defined as a documented history of recurrent Level 2 events, where glucose is measured below 54 milligrams per deciliter (mg/dL).
Alternatively, qualification is met by documenting at least one Level 3 hypoglycemic event. A Level 3 event is severe enough to require assistance from another person for treatment. Regardless of the diagnosis, the treating practitioner must conclude that the patient meets the necessary medical criteria.
Specific Use and Management Requirements
Medical eligibility alone is often insufficient; patients must also demonstrate the ability and willingness to actively use the device. Continuous coverage requires proof that the patient remains committed to their overall diabetes treatment plan and shows evidence of consistent device usage.
Before the device is prescribed, the patient or their caregiver must receive sufficient training in its proper use. This training ensures they understand how to apply the sensor, interpret the data, and make appropriate adjustments to their insulin or other therapies. The prescription for the CGM system can often serve as the documentation that this initial training has taken place.
A structured relationship with the healthcare provider is mandated to ensure the data is used therapeutically. The treating practitioner must have an in-person or Medicare-approved telehealth visit with the patient within six months before ordering the CGM. This visit evaluates the patient’s diabetes control and confirms eligibility criteria are being met. The provider is responsible for documenting that the patient requires adjustment to their treatment regimen based on the glucose results.
For continued coverage after the initial prescription, the patient must have a follow-up visit with the provider at least every six months. During these bi-annual encounters, the provider must document the patient’s adherence to the CGM regimen and their overall diabetes treatment plan. A short-term trial using a professional CGM system can be used to assess readiness.
Navigating Insurance and Coverage Standards
Financial qualification often involves meeting strict standards imposed by payers, which may exceed the medical necessity established by a physician. Major public payers, such as Medicare, classify the CGM system as Durable Medical Equipment (DME) and provide coverage under Part B. These rules set a strong precedent that many private insurance companies follow.
Current Medicare coverage criteria require the patient to have a diabetes diagnosis and be treated with insulin, or have a history of problematic hypoglycemia. The device must be prescribed in accordance with its FDA-approved indications for use. Importantly, the physician must explicitly document in the patient’s medical chart that all these coverage requirements have been met.
While Medicare coverage has expanded, private insurance coverage varies significantly, especially for individuals with Type 2 diabetes not on intensive insulin therapy. Clinical guidelines increasingly support CGM use for individuals treated with non-intensive insulin or non-insulin medications. However, coverage for these less-intensive patient populations is often limited or non-existent.
Even when coverage is approved, the patient is responsible for specific out-of-pocket costs. Under Medicare Part B, the patient pays a deductible, followed by a 20% coinsurance for the CGM and related supplies. If the patient has a Medicare Advantage plan, coverage must be at least equivalent to Part B, though co-payments and deductibles may differ based on the plan. Qualification is not permanent; it is tied to required six-month check-ups where the provider must confirm the patient continues to meet the criteria for ongoing use.