Dexcom 90-Day Supply Ordering Quantities
For a 90-day supply of Dexcom continuous glucose monitoring, order 9 sensors (for Dexcom G6) or 9 sensors (for Dexcom G7), plus 1 transmitter (G6 only, as G7 has integrated transmitter), and 1 receiver if the patient doesn't use a compatible smartphone.
Sensor Quantities
The calculation is straightforward but requires understanding real-world wear patterns versus labeled duration:
- Dexcom G6: Labeled for 10 days of wear, requiring 9 sensors for 90 days (90 ÷ 10 = 9)
- Dexcom G7: Labeled for 10 days of wear, requiring 9 sensors for 90 days (90 ÷ 10 = 9)
However, real-world data shows most sensors are worn for less than the labeled 10 days. A 2025 study found that median Dexcom G7 sensor wear time was only 8.6 days in youth with type 1 diabetes, with just 39.9% of sensors worn for ≥10 days 1. This means patients may actually need 10-11 sensors to achieve truly continuous 90-day coverage without gaps.
Transmitter Requirements
- Dexcom G6: Order 1 transmitter per 90 days (transmitter lasts 90 days)
- Dexcom G7: No separate transmitter needed (integrated into each sensor)
Receiver Considerations
Order 1 receiver only if:
- Patient lacks a compatible smartphone
- Patient prefers not to use smartphone app
- Backup device is desired for reliability
Most patients use their smartphone as the receiver, making a separate device unnecessary 2.
Critical Ordering Pitfalls
Gap prevention is essential: The 2025 ADA Standards emphasize that "people with diabetes should have uninterrupted access to their supplies to minimize gaps in continuous glucose monitoring" 2. Real-world sensor survival rates show that Dexcom G7 has a 90.3% 10-day survival rate 3, meaning approximately 1 in 10 sensors may fail prematurely.
Consider ordering 10 sensors instead of 9 for the following patients:
- Youth and young adults (median wear 8.6 days) 1
- Patients with history of sensor failures
- Patients with skin reactions requiring early removal 2
- Patients who need continuous coverage without any gaps
Insurance Coverage Context
Most commercial insurance and Medicare cover CGM supplies at 90-day intervals 4. The standard prescription is typically written as "9 sensors per 90 days" based on the 10-day labeled wear time, but clinical judgment should guide whether to request additional sensors for patients at risk of gaps in coverage.
The evidence strongly supports CGM use: Guidelines recommend real-time CGM or intermittently scanned CGM for all adults and youth with diabetes on any type of insulin therapy 2, with demonstrated improvements in time in range, hypoglycemia reduction, and quality of life 5, 6, 4.