Expanding the Field: Who Now Qualifies for CGM, AID, and Continuous Ketone Monitoring?

In an interview with Pharmacy Times for the 2026 Diabetes Day of Education, Natalie Bellini, DNP, FNP-BC, BC-ADM, assistant professor of medicine and program director of diabetes technology at Case Western Reserve University/University Hospitals, discussed how evolving clinical guidelines are broadening the eligible patient population for advanced diabetes technology.

Bellini outlined how continuous glucose monitoring (CGM) candidacy has expanded beyond patients with hypoglycemia to include anyone whose glucose fluctuations need to be better understood—noting that CGM data can directly inform medication selection. She explained that automated insulin delivery (AID) system eligibility has similarly expanded, with new guidance recommending AID initiation when patients on basal insulin are not at their goals and mealtime insulin is being considered. Bellini also spotlighted continuous ketone monitoring (CKM) as an emerging technology poised for wider use in 2026, with applications for patients with type 1 and type 2 diabetes and the potential to enable safer sodium-glucose cotransporter 2 (SGLT2) inhibitor use in type 1 diabetes.

Pharmacy Times: What are the key factors that guide identifying the right candidate for CGM?

Natalie Bellini, DNP, FNP-BC, BC-ADM: Some of the guidelines have changed about the right candidate for CGM because we used to say the right candidate had hypoglycemia. In the early days of CGM, you had to actually demonstrate hypoglycemia in order for an insurance company to pay for it. The American Diabetes Association guidelines have changed. They said, “OK, this is really beneficial for people with type 1 diabetes.” Then they said, “Maybe for people with type 2 diabetes who take insulin or sulfonylureas and have lows.” The most recent guidelines say those people with type 1 diabetes have the most significant fluctuations in glucose and are at the highest risk for hypoglycemia because they’re reliant on insulin for everything that they do. When we look at people with type 2 diabetes, the new guidelines say those who benefit should receive it.

To me, as a clinician and the director of diabetes technology at my health system, those who benefit are anyone where we need to understand when their glucose fluctuates. Someone might check their glucose first thing in the morning, and fasting tends to be the lowest number of the day, and they say, “Well, I’m 128 in the morning, sometimes as high as 150 if I had a big pasta dinner the night before,” but their hemoglobin A_1C comes in at 8.2. What medication do I use? I can’t tell you because I don’t know when they’re high. If they’re high post meal, I might use a glucagon-like peptide-1 (GLP-1) receptor agonist. We look at those factors when we get that CGM data to know what to do next.

Pharmacy Times: What about key factors for the right candidate for AID?

Bellini: Again, the ADA guidelines say people with type 1 diabetes should be offered an AID. They don’t all choose it, but they need to be offered it. That is the delivery method of choice because we get the highest time in range on those CGMs, and we can reduce hypoglycemia. When we look at people with type 2 diabetes, the guidelines used to say when they’re on real-time insulin and basal insulin, you should then consider an AID system. Now the guidelines say if they’re on basal insulin and not at goal, and you’re considering adding mealtime insulin, put them on the AID then because that’s the next step. This actually increases the potential number of people that would benefit from AID exponentially.

Pharmacy Times: And lastly, key factors for identifying the right person for CKM?

Bellini: Continuous ketone monitoring—here we go. This is it. This is 2026. It’s coming, hopefully this year. When we look at CKM, first we can talk about people with type 1 diabetes because they have the highest risk of diabetic ketoacidosis (DKA). Those people are not making any insulin, and if insulin delivery stops for some reason, or they end up with vomiting, dehydration, gastrointestinal problems, or illness alone, they can end up with ketones very quickly. Fasting can also lead to ketones, so that’s an easy identifier. Then we need to take a step back and look at people with type 2 diabetes. Type 2 diabetes is a progressive disease, and beta cell function falls over time. As beta cell function falls, the risk of DKA goes up. Those are another whole group of people whom we are absolutely going to use CKMs for.

The other thing is, if we take a step back and look at people with type 1 diabetes, SGLT2 inhibitors have been identified as a way to protect the kidney and slow down the progression of kidney disease. We’re not supposed to use them for people with type 1 diabetes because there’s an increased risk of euglycemic DKA. Well, if I can use a CKM, I can protect that person’s kidneys and know if they’re having a problem. We’ve got options for people with type 1 diabetes now, for different reasons, and options for people with type 2 diabetes. I think we’re going to use a lot of them.