The papers in this special Health Affairs collection offer a fresh and very important look at Medicare's future. Taken as a whole, they suggest that financing problems in Medicare will be particularly acute in coming decades. Other pieces of evidence suggest that this outlook is not as problematic, however. The technological changes that the RAND authors consider will likely come to pass, and they will drive up Medicare spending (often with good value). But there is enormous potential for cost savings as well, which we have the capacity to realize.