Continuous glucose monitoring (CGM) is a medical device that helps people with diabetes to monitor their blood sugar levels continuously throughout the day. Medicare covers continuous glucose monitoring devices for people with diabetes who meet certain conditions. 

Here are the conditions for billing a continuous glucose monitor through Medicare: 

• Eligibility: To be eligible for Medicare coverage of a CGM, the patient must have type 1 or type 2 diabetes and must use insulin to control their diabetes. 
• Prescription: The patient must have a prescription from a healthcare provider for the CGM. 
• Frequency of use: The patient must use the CGM at least three times per day. 
• Clinical necessity: The patient’s need for a CGM must be deemed clinically necessary by their healthcare provider. 
• Supplies: Medicare covers the cost of the CGM device and the necessary supplies, such as sensors, transmitters, and receivers. 
• Durable Medical Equipment (DME) provider: The CGM must be provided by a durable medical equipment (DME) supplier who is enrolled in Medicare. 
• Co-payments: The patient may be responsible for paying a portion of the cost of the CGM, such as a deductible, co-insurance, or co-payments. 

It’s important to note that Medicare coverage for continuous glucose monitoring devices may change, so it’s a good idea to check with Medicare for the most up-to-date information. Also, coverage for CGMs may vary by state, so patients should check with their Medicare plan for more information on their specific coverage.