I Am Researching The Dexcom CGM For My Husband Who

I am researching the Dexcom CGM for my husband who is a Type 1 diabetic. Does he need to have an insulin pump in order to use this device? I saw on the website that you insert the sensor similarly to an insulin injection. They mentioned inserting a new one every 7 days or so. What happens to the old ones? Do they stay in your system? Is there any chance of them "moving" or "floating" to dangerous places? Do you happen to know if the VA covers the cost of this device?

Thanks!