When the state-based insurance exchanges open next year under Obamacare, many Americans should finally have access to affordable insurance. But millions of others will most likely be left out in the cold and remain uninsured. These folks -- mainly low-income adults in the 21 states that aren't expanding Medicaid -- will not be eligible for either the long-standing government health insurance program for the poor, or for premium subsidies in the new exchanges. Some 4.9 million people will not be covered in 2016 if these states don't expand, according to the Urban Institute. Another 1.5 million uninsured are in six states that are considering expansion, but have yet to approve it.
