This report assesses the changes in coverage patterns and health care costs that will occur nationally if major reforms are not enacted. The authors find that by 2015, there could be 59.7 million people uninsured.  

From the report:

This report makes clear that the cost of failure would be high and the status quo is probably unsustainable. The analysis shows that if federal reform efforts fail, over the next decade, the percent of the population that is uninsured will increase, employer-sponsored coverage will continue to erode, spending on public programs will balloon, and individual and family out-of-pocket costs will rise.

Full report: http://www.urban.org/health_policy/url.cfm?ID=412049

Urban Institute. (2010). The cost of failure to enact health reform (2010-2020). Garret, B., Buettgens, M., Doan, L., and Holahan, J.