A PFFS plan works differently than a Medicare supplement. By joining a Medicare PFFS plan, you consent to pay the plan’s premiums, plus copays and coinsurance for medical services as defined in the plan.
What separates these plans from an HMO or PPO is that you’re not restricted to any particular network of providers. Instead, you present your insurance plan ID card to any provider at the time of service. Before they treat you, the provider has to agree to approve the plan’s payment terms and conditions and render the plan.