sentences:  MD² clients have insurance to cover additional services beyond primary care, but MD²'s fees cover the full costs of their services and MD² does not bill insurance.MD²'s approach became widely known very quickly, and many physicians sought to emulate the model in a less costly fashion.MDVIP emerged as a competitor to MD² with a similar model, but they opted to bill insurance in addition to charging client fees and have patient loads of up to 600.