So, who ARE the remaining 33 million uninsured?
acasignups.net

That should knock the uninsured populations down to something like:

6.5 million: Undocumented Immigrants

3.7 million: Medicaid Gap

3.5 million: Eligible for Medicaid/CHIP

7.9 million: Between 100–400% FPL (tax credits)

8.6 million: Over 400% FPL

This still leaves around 2.8 million people unaccounted for. On the one hand, that’s an awful lot of people. On the other hand, given all the estimates, rounding, population growth and churn swirling around as everyone’s situation changes from month to month, that seems like a pretty good breakdown to me.