The Congressional Budget Office estimates that 21 million people will have enrolled in a health plan through the Affordable Care Act’s marketplaces in 2016. The Obama Administration is projecting just half of that, with a target of just 10 million enrollees by the end of the third open enrollment season (OE3). And one of the best ACA enrollment number crunchers out there, Charles Gaba of ACAsignups.net, projects a number in the middle – 14.7 million enrolled in marketplace plans.

There are several good reasons for enrollment to be lower than CBO projections. Many people haven’t explored the ACA’s marketplaces because they remain on non-ACA compliant policies that they’ll be allowed to renew into 2016, thanks to the Obama Administration’s transitional policy. It’s not clear how many have opted to stay on their pre-ACA plans, but surveys suggest it’s at least 16 percent of people currently insured in the non-group market. Funds for public outreach, education and enrollment assistance have also been limited. It’s thus not surprising that 6 in 10 of the currently uninsured say they’re either confused or have not heard about the tax credits available to make coverage more affordable.

So who will prove right when it comes to 2016 marketplace enrollment projections? I’m not convinced it matters. Ultimately the ACA is about providing people with improved access to care, better health outcomes, and some financial peace of mind. Although it’s too early to know whether the ACA is meeting those goals, there are signs that we’re moving in the right direction.

Since the ACA has been enacted, we’ve seen the largest reduction in the number of uninsured people in decades, with 16.4 million gaining coverage since the ACA was enacted. Recent surveys show that the majority (83 percent) of those enrolled in marketplace coverage value their insurance, and fewer people than ever before are reporting problems paying medical bills. Health care cost growth has slowed, with premiums rising just 4 percent last year, compared to double-digit year-to-year increases before the ACA was enacted. These are all metrics we can and should continue to track. But not because any one metric at any given point of time is “proof” that the ACA is a success. It’s because, taken as a whole, these numbers point to whether or not we’re on track to meet our ultimate goal of a healthier population with greater financial security. So far, I’d say we are.