Because of the new health care law, “2.5 million young adults now have coverage.”

The Road We’ve Traveled — a 17-minute film from President Barack Obama’s re-election campaign — touts his achievements in health care, saying that the Affordable Care Act has substantially expanded coverage for millions of Americans.

We’re checking several claims from the film, including one that “2.5 million young adults now have coverage.”

The law requires insurers to provide dependent coverage for children up to age 26 on all policies. The goal is to prevent young adults from becoming uninsured when their parental or college plans would otherwise run out. This provision took effect in September 2010.

We found support for the film’s statistic in a Health and Human Services analysis of data from the National Health Interview Survey, a longstanding survey conducted by the federal Centers for Disease Control and Prevention. The survey found an 8.3 percentage point increase in insurance coverage for the 19-to-25 age group between the third quarter of 2010 and the second quarter of 2011 — from 64.4 percent to 72.7 percent. The analysis then multiplied 8.3 percent by 29.7 million — the number of people nationally in that age group — to come up with the number 2.5 million.

We’ll note that the original CDC study, using slightly different methodology, found a smaller number. Using annual and semi-annual figures rather than quarterly numbers, the number grew by 1.3 million.

The HHS analysis makes the case that, for various technical reasons, its method is superior. We think both estimates are reasonable, and while the 2.5 million figure got more traction in the media, we also think it’s worth noting that the underlying federal study offers an alternative — and smaller — number. In essence, the film cherry-picks the higher number. So the statement is accurate but needs clarification, which fits our definition of Mostly True.