What is the proper procedure for ordering a Dexcom (continuous glucose monitoring system) G7 sensor?

How to Write an Order for Dexcom G7 Sensor

To order a Dexcom G7 sensor, write a prescription that includes: the device name "Dexcom G7 Continuous Glucose Monitoring System," quantity of sensors needed (typically 3 sensors per month for continuous 10-day wear cycles), the transmitter if this is an initial order, diagnosis code (diabetes type), and clinical indication justifying medical necessity.

Essential Prescription Components

Device Specifications

• Specify "Dexcom G7 rtCGM System" - this is FDA-approved as an integrated CGM (iCGM) for nonadjunctive use, meaning patients can make insulin dosing decisions without confirmatory fingerstick testing 1
• The G7 sensor has a 10-day wear period (with investigational 15.5-day versions showing similar accuracy) 2, 3
• Each sensor is a single-use, disposable unit that combines the sensor and transmitter in one wearable device 2

Quantity and Supply Duration

• Order 3 sensors per 30 days for continuous monitoring coverage (10 days per sensor × 3 = 30 days) 1
• Include the receiver/display device if the patient doesn't have a compatible smartphone 1
• Specify "uninterrupted access to supplies" as gaps in CGM use reduce clinical benefit 1

Anatomical Placement Site

• Specify either upper arm or abdomen placement - both sites show excellent accuracy, with arm placement achieving 8.2% MARD and abdomen 9.1% MARD 2
• The sensor is implanted subcutaneously at these sites 1

Clinical Justification Requirements

Diagnosis Documentation

Include the specific diabetes type and treatment regimen:

• Type 1 diabetes (any insulin regimen) 1
• Type 2 diabetes on intensive insulin therapy (≥3 injections daily or insulin pump) 1
• Type 2 diabetes on basal insulin or mixed therapies 1
• Gestational diabetes or diabetes in pregnancy 1, 4

Medical Necessity Indicators

Document at least one of these clinical scenarios to support insurance authorization:

• Unexplained severe, recurrent, asymptomatic, or nocturnal hypoglycemia 1
• Unexplained hyperglycemia, especially fasting 1
• Dramatic glycemic variability 1
• HbA1c above target despite multiple medications 1
• Hypoglycemia unawareness 1
• Need to achieve specific glycemic goals (time in range 70-180 mg/dL) 1

Patient Education Requirements

The prescription should trigger mandatory diabetes education covering:

• Daily sensor wear is essential - clinical benefit correlates directly with frequency of use 1
• No fingerstick calibration required (G7 is factory-calibrated) 1
• Potential interfering substances: high-dose acetaminophen (>4g/day), salicylic acid, ascorbic acid 5
• Critical contraindication: Do NOT use in patients on peritoneal dialysis due to icodextrin interference with glucose oxidase-based sensors 5

Special Population Considerations

• Hemodialysis patients: Note that G7 accuracy in hemodialysis has not been specifically validated; the older G6 showed reduced accuracy (22.7% MARD) in this population 6
• Pregnancy: G7 is accurate and safe throughout pregnancy with 83.2% of values within 15% of reference in the 70-180 mg/dL range 4

Sample Prescription Format

Dexcom G7 Continuous Glucose Monitoring System
- Sensors: 3 per 30 days (10-day wear each)
- Placement site: Upper arm or abdomen
- Diagnosis: [Type 1/Type 2/Gestational] Diabetes Mellitus (ICD-10: E10.xx/E11.xx/O24.xx)
- Clinical indication: [Specify: hypoglycemia unawareness/glycemic variability/intensive insulin therapy/etc.]
- Refills: 12 months
- Patient requires intensive diabetes education for CGM implementation

Common Pitfalls to Avoid

• Don't order without specifying quantity - vague orders like "CGM supplies as needed" will be rejected by insurance 1
• Don't forget to document the clinical indication - third-party payers require justification for coverage 1
• Don't prescribe for patients with depression/anxiety without additional support - real-time alerts may worsen these conditions 1
• Don't assume all patients can use smartphone apps - some will need the dedicated receiver device 1
• Verify the patient is not on peritoneal dialysis before prescribing any glucose oxidase-based CGM 5