The Greenwich resident -- whose office in the sprawling WestMed facility located just off the Playland Parkway, in nearby Rye, N.Y., features at least one framed photograph of Fass smiling next to Barack Obama -- has long been a champion of both the president and his health-care reform plan. Working with Doctors for America, a national organization that grew out of Obama's 2008 campaign, Fass has provided input to the administration on its Patient Protection and Affordable Care Act. He was one of 150 physicians from across the country who attended the White Coats at the White House event in October 2009, helping Obama make the case for reform. Fass, who offers a form of radiation therapy that can spare healthy tissue surrounding a tumor, agrees that the insurance-approval process is onerous. He also agrees that Medicare, the federally administered program for people over 65, is not sustainable on its present course.