Don Berwick, MD, the administrator in charge of Medicare and Medicaid, was having dinner in Dupont Circle not long ago with five of his predecessors when the conversation veered to how long he could keep his job. In the realms of healthcare, his is a pivotal role: overseeing two entitlement programs that insure nearly one in three Americans, sheperding the profound insurance changes spurred by the new healthcare law and serving as chief cheerleader for better care at lower cost. A pioneer in improving medical quality, but a neophyte in Washington politics, Berwick ran into a buzz saw of Republican opposition over old academic writings when President Obama chose him for the task 16 months ago. A year ago this week, the president slid him into the job without Senate confirmation while Congress was out of town. The "recess appointment" installed Berwick at the helm of the Health and Human Services' Centers for Medicare and Medicaid Services. But, unless the Senate acts, he cannot stay beyond December.