It’s as unfortunate as it is unsurprising: young, low-income women—the very people whose lives are often turned upside-down if they become pregnant—are less likely to use birth control if they have to pay for it. And high up-front costs are a big part of the reason they’re far less likely to use the most effective methods, like IUDs. Time and again, research has demonstrated that if contraception is offered for free, more women use it.

That’s why advocates who want all women to have access to the full range of contraceptive methods were united in their support of the Affordable Care Act (ACA). That’s why they used every tactic—from mass mobilization to litigation to political horse-trading—to press their case. When the rules were written, they got much of what they wanted: legislation that expands health insurance to those previously excluded from the system, covering every contraceptive method with no co-pay. In a country with a fragmented health care system, fractious politics, and a deep ambivalence about the role of government, it was a major victory.

Among the many hopes for the Affordable Care Act, certainly one has been that the extension of health insurance will help women control whether and when they become pregnant. In theory, a lower price to consumers, particularly low-income consumers, should mean greater demand for birth control, including methods that protect from pregnancy for months or years. And more use of the most effective methods should mean greater control for women over their futures, fewer unintended pregnancies, and all the benefits that go along with those things.

That’s the theory. The reality is that to get to these outcomes that are so good for women, families, and society requires that a whole bunch of things work well. People who otherwise would not be able to afford preventive services like contraception counseling and care have to sign up for the newly available insurance. Private as well as public insurers have to follow the letter and the spirit of the law: all methods, no co-pay, no funny business. Providers have to be willing and able to provide quality care, including long-acting methods that they are less familiar with than the easy-to-dispense Pill. Women have to make the effort to get and use the birth control method that’s right for them. Oh, and the whole system has to remain solvent.

Whether the reality bears out the theory will be revealed in the data, if we watch carefully. Now that we’re close to a year into implementation, we’re starting to see that some of the links in the chain are strong while others need reinforcement.

To start: we now know that when insurance coverage was offered, people signed up. There are now far fewer young and low-income people who are uninsured; women, more than men, have taken advantage of the new availability of good insurance coverage. (The New York Times has a great overview.)

We also know that American women with private insurance are paying far less for some kinds of birth control, but not all of them. A recent analysis by the Guttmacher Institute showed that 40 percent of women who use the Pill now get it for free, up from 15 percent before the Affordable Care Act went into effect. Among women using the vaginal ring, 52 percent now pay nothing for their prescription—a big change from the 23 percent before the ACA. Those are big, quick improvements.

But that same study shows that a large share of women who use the IUD are still paying significant amounts out-of-pocket. This suggests that insurers may not be providing a full package of benefits, as stipulated by the law, and they may still be demanding some co-pay. At least as troubling, the Guttmacher analysis shows that even public insurers in some states may be charging for birth control.

So the agenda for policy research and action is starting to come into focus. On the consumer side, we need to continue to watch both the raw numbers and the kinds of contraceptive and other preventive care services being used. We need to know whether, despite the no co-pay rule, price continues to be a barrier to the use of long-term methods. We also need to know which women are most likely to use more and better contraception when they’re not paying for it, and which women face non-financial barriers that aren’t addressed by the ACA and require different efforts.

On the insurer side, we need to understand whether the combination of the broadened benefit package and the larger risk pool is making for a financially sustainable model, and whether this is likely to continue as consumer demand evolves.

On the provider side, we need to know whether a full range of methods is being offered (at a high standard of quality) at facilities, including health centers that have not traditionally specialized in providing contraceptive care.

Finally, to truly see whether this landmark legislation is affecting important outcomes, we need to trace the effect on the incidence of unintended pregnancies over time—methodologically challenging, but possible because implementation varies around the country and we have lots of natural experiments to learn from.

Studying the steps in implementation and impact is not an academic exercise, although it requires academic rigor. Instead, this sort of timely policy research is just the sort of information that can help preserve the best of the ACA, and fix the rest.