I know that they offer payment plans for those paying cash directly from them, and I don’t know the sure, but I would guess that they’d do the same for co-pays. The problem is, not many insurance companies allow you to buy directly from the manufacturer. Most want you to get your products through a DME distributor. So it’s that distributor you would owe the balance to, not Tandem. So Tandem can’t really help you with that.
Your best bet is to call Tandem sales and ask them to do a benefits check. They’ll be able to tell you it they can fulfill your order directly, or if not, which DME suppliers you can use. Once you know your options, you can call around and see who offers payment plans. Or maybe do a little internet research on the companies.