Earlier today, Congressional Budget Office director Douglas Elmendorf testified to the Senate Finance Committee about various healthcare proposals, and his remarks are here ("Options for Expanding Health Insurance Coverage and Controlling Costs").

Evaluating the various claims is left for those more familiar with these issues, however one issue in our purview is this:

[CBO estimates that] the average number of nonelderly people who are uninsured will rise from at least 45 million in 2009 to about 54 million in 2019.

1. The number for the current number of uninsured you'll most likely hear is 47 million, based on 2006 Census Bureau figures. That number fell to 45.7 million in 2007, and as far as I know it included the non-elderly as well.

2. As pointed out several times (link, link, link), the usual formulation is that there are "47 million uninsured Americans", which is a rather big lie: millions of that number are actually citizens of other countries, with some of them being here illegally. Note that Elmendorf did not use that incorrect formulation, but that's not going to stop others from lying about this issue.

3. One very effective way to reduce the number of uninsured would be to actually enforce our immigration laws, something that Elmendorf doesn't discuss. The only thing he says about that is issue is this:

The treatment of certain populations would present various administrative challenges for proposals to expand coverage. Some individuals, including military personnel and veterans, already receive health benefits from the federal government, and issues might arise regarding the coordination of their current benefits with new federal subsidies. In other cases, federal health programs currently deny benefits to certain populations, such as unauthorized immigrants or prison inmates, and proposals would have to specify whether and how those restrictions would apply to new programs. Other populations, such as the homeless, face challenges enrolling in existing programs, and similar issues might arise in designing new subsidies for health insurance. Those considerations would affect both the costs of proposals and their overall impact on rates of insurance coverage.