Clarification about the 3.1 Million "Under-26'ers" figure

OK, exhausted from the frenzy of activity today, but I did want to get one issue cleared up as best as I could. There's a lot of confusion about the "3.1 million young adults on their parents plan" figure which is mentioned on the graph but not referred to in the spreadsheet itself.

The 3.1 Million figure comes from a CNN Money article from June 2012. According to that article, the comparable number a year earlier (June 2011) was 2.5 million, so it's safe to assume that this number has only gone up further in the past 18 months.

However, according to the Kaiser Family Foundation (h/t to "Nadeem" for the heads up), the actual number may be even higher; see this story from October of this year, which cites, in turn, a 2013 tracking survey by the Commonwealth Fund which lists the number as far higher: 7.8 Million:

There is concern that many young adults (ages 19–29) will remain without health insurance in 2014 despite the Affordable Care Act’s reforms, including subsidized private coverage offered in new state marketplaces and expanded Medicaid eligibility. How things turn out will likely depend on outreach efforts and states’ decisions on expanding Medicaid. Commonwealth Fund Health Insurance Tracking Survey data from 2011 and 2013 show increasing awareness among young adults of the 2010 requirement that health plans cover chil- dren under age 26. Of the estimated 15 million young adults enrolled in a parent’s plan in the prior 12 months, 7.8 million would not likely have been eligible to enroll prior to the law. Still, only 27 percent of 19-to-29-year-olds are aware of the marketplaces. Meanwhile, most uninsured young adults living below poverty will not have access to subsidized public or private insurance in states opting out of the Medicaid expansion. 

Given the craziness of the past few days, I haven't had a chance to check into this further, but assuming it checks out, it certainly looks like 7.8 million is the more appropriate number to use. Of course, if I do change it from 3.1 to 7.8 I'll no doubt be accused of making up phantom numbers, so I'll have to double-check before proceeding.