Medigap preferred provider organizations: issues, implications, and early experience.

The Health Care Financing Administration is sponsoring the Medicare Physician Preferred Provider Organization (PPO) Demonstration to assess the feasibility and desirability of including a PPO option under Medicare. Two sites are currently operational. At one site, Blue Cross and Blue Shield of Arizona is offering a PPO linked with a medigap insurance plan. This "medigap PPO" and its initial experience are described, and a preliminary assessment of the viability and effectiveness of medigap PPOs nationally is provided. Impediments to the development and effectiveness of medigap PPOs are identified and possible government actions discussed.