In between sets of tumbling warmups, Adrienne Prashar crossed the gym to where she had stashed her diabetes supplies and tested her blood sugar. Prashar, who was diagnosed with Type 1 diabetes the day before her 13th birthday, said tumbling usually drops her blood sugar levels.

Prashar, now 14, did a finger stick, saw her blood sugar was 127, and went back to the mat. For most people with diabetes, the target range is about 80-130, and up to 180 two hours after meals.

Prashar doesn’t have to check her blood sugar often. She wears a continuous glucose monitor, or CGM, that gives her blood glucose readings on her phone every five minutes. When she’s feeling differently than her CGM is showing, as on that March day at the gym, she checks her level by doing a finger stick.

But most of the time, she simply glances at her phone to see whether her numbers are trending low or high, which beats repeatedly pricking her finger, she said.

“I would hate it so much,” Prashar said. “It’s such a pain and it’s harder to see trends.”

Montana lawmakers are considering a bill that would require insurance companies to cover CGMs for people with Type 1 and Type 2 diabetes. Multiple studies and experts back up the effectiveness of the devices, showing better blood test results, fewer long-term complications, and a reduction in health care costs.

Studies show CGMs can greatly benefit people with Type 1 diabetes. There are also promising results for people with Type 2 diabetes, the more prevalent of the two types, but the research is limited compared with that on Type 1.

House Bill 758 has broad support from lawmakers, but it faces opposition from insurance companies and some providers. That opposition focuses on the cost, whether a CGM is medically necessary at all stages of diabetes, and the possibility that CGM manufacturers will raise their prices if there is an insurance mandate.

CGMs can be worn on the legs, stomach, or arms, and they stay in place with an adhesive patch. A thin tube goes under the skin and measures blood glucose levels from tissue fluid. The data is transmitted via Bluetooth to a phone or similar device. Instead of a finger prick, which provides a reading for a single point in time, a CGM gives the wearer a continuous stream of data.

According to GoodRx Health, CGMs can cost between $1,000 and $3,000 each year out-of-pocket.

Blue Cross and Blue Shield of Montana, the state’s largest insurer, estimates the bill, if passed, would cost the organization nearly $5 million a year, spokesperson John Doran said.

CGMs aren’t medically necessary in all circumstances, Doran said, and medical necessity should be determined through a partnership between provider and payer. But Doran said that he understands there are instances in which a CGM may be necessary and that Blue Cross already covers CGMs in those cases.

“These things are a convenience,” Doran said. “They provide you real-time information and there is some benefit to a person’s lifestyle to these monitors.”

Lawmakers in several states are considering bills to regulate coverage of CGMs, and Illinois’ governor signed one such bill into law last year.

A study published in the Journal of Diabetes Science and Technology in 2022 says about 30 million Americans have diabetes, a condition in which a person’s body can’t make enough insulin (as in Type 1) or use it effectively (as in Type 2). By 2030, the study estimated, 55 million people in the U.S. will have diabetes, with total medical and societal costs of more than $622 billion — a 53% increase from 2015. According to the American Diabetes Association, nearly 78,000 Montanans have been diagnosed with diabetes.

Various studies, diabetes educators, and health care providers say that CGMs can help people with diabetes reduce their A1C levels, a common measure of blood sugar levels used in diabetes management. Proper management can reduce complications from diabetes — like retinopathy, heart attack, and nerve damage — that lead to higher costs in the health care system through emergency room visits and hospitalizations.

Dr. Brian Robinson, an endocrinologist at St. Peter’s Health in Helena, said supplies for people with Type 1 diabetes are generally covered by insurance. When he considers recommending a glucose monitor for a patient, he said, the decision is driven by insurance rules that are informed by the American Diabetes Association’s standards of care.

“My patients are better because of CGMs, there’s no doubt about that,” Robinson said. But he noted the science doesn’t yet support his opinion that CGMs should be given to everyone with diabetes, no matter what.

Not all physicians, especially in endocrinology, agree that a person with Type 2 diabetes needs a continuous glucose monitor, Robinson said. But if a person needs a shot each day to manage diabetes, he said, that patient should have access to a CGM.

Lisa Ranes, manager of the diabetes, endocrinology, and metabolism center at Billings Clinic, said the benefits of a CGM are the same for people with Type 1 and Type 2 diabetes.

Many studies have shown that CGMs are just as effective for patients on lower quantities of insulin, like some people with Type 2 diabetes, as for people with Type 1 diabetes, who rely on insulin throughout the day.

“It gives patients that complete picture to help them make the decisions on what they need to do to keep their blood sugar safe,” Ranes said, giving examples like upping the frequency or dose of insulin, having some food, or exercising.

For people with Type 2 diabetes, Ranes said, CGMs could be helpful in early diagnosis. Type 2 diabetes is progressive, Ranes said, so the sooner it is under control, the better.

When Cass Mitchell, 76, was diagnosed with Type 2 diabetes over 30 years ago, her doctor told her that people with Type 2 diabetes don’t live long because they have a hard time managing their care.

Mitchell, who lives in Helena, warmed to finger pricks. But test strips were expensive, about $1 each at the time, she said.

About 10 years ago, she got a CGM. Mitchell went from testing maybe twice a day to looking at her blood sugar on an app 20 to 25 times each day. She said she’s more in tune with her diabetes and uses her device’s time-in-range reports — showing how often blood glucose stays within a set range — to make lifestyle changes.

Mitchell has lowered her A1C from around 11% to 7%. According to the ADA, the target for most adults with diabetes is less than 7%.

Mitchell’s device is covered under Medicare and supplemental insurance and would remain so with the passage of HB 758. She said if she had to pay out-of-pocket she wouldn’t be able to afford her CGM and that she was excited about the potential of the bill to give more people access to CGMs.

Dr. Hayley Miller, medical director of Mountain States Diabetes in Missoula, initially thought HB 758 sounded good, but now she isn’t so sure. She thinks the biggest risk of the bill passing is that prices for CGMs go up.

“It seems like I’m against it, but it really is, when insurance gets involved everything gets tricky,” Miller said.

Emma Peterson, a former diabetes educator for St. Vincent Healthcare in Billings and Providence Endocrinology in Missoula, said most people working in diabetes care think everyone diagnosed should just have a continuous glucose monitor.

“At the end of the day, both forms of diabetes and all the other many forms of diabetes have the same complications and still face the same struggles of trying to keep blood sugars in range,” Peterson said.

Keely Larson is the KHN fellow for the UM Legislative News Service, a partnership of the University of Montana School of Journalism, the Montana Newspaper Association, and Kaiser Health News. Larson is a graduate student in environmental and natural resources journalism at the University of Montana.

By Keely Larson
Kaiser Health News is a nonprofit news service covering health issues. It is an editorially independent program of the Kaiser Family Foundation, which is not affiliated with Kaiser Permanente.