I would also want to know if a secondary is involved. As for ownership of the equipment, if your billing is for a purchase and you waive co-pay/or out of pocket, the patient would retain ownership, as you are agreeing to write off the out of pocket. So long as this is not done "routinely" and there is a hardship agreement and you have billed both carriers it is legal. In my opinion if there is a secondary, I would not write off if the secondary is going to pay a good portion of the out of pocket.