It's a common refrain about the Affordable Care Act: The law will become more popular as benefits take effect. But what happens if the benefits start to roll out, and nobody notices?

That's a pretty pertinent question right now, as two high-polling benefits rolled out on Aug. 1: no co-pays for contraceptives and $1.1 billion in insurance rebate checks for 12.8 million American families.

Both are incredibly well-liked. But as an insurance subscriber, it is incredibly difficult to know whether you have access to either of them.

Let's start with the rebate checks that insurance companies have to pay out if they don't spend at least 80 percent of subscriber premiums on health care claims. About 20 percent of those rebates went to subscribers in the individual market, meaning a check showed up in their mailbox.

The other 80 percent - 10.2 million rebates - went to families enrolled in employer-sponsored insurance. In those cases, the health insurance plan will send a rebate to the employer. It is then the employer’s responsibility to either pass that rebate on to the individual or use it in other ways that may benefit the employee, such as lowering premiums for the next year.

That's where things can get muddled: Only 2 percent of companies recently surveyed by the National Business Group on Health plan to cut rebate checks for their employees. They're significantly more likely, as you can see in this chart, to put it towards the next year's premiums or covering administrative costs. This could change, it's worth noting, as a lot of companies haven't made up their minds quite yet.

“We’re seeing a very high increase in the number of calls that H.R. call centers are handling from employees saying, ‘Where’s my money?’ ” Mendy Stein, a health care specialist with benefits consulting firm Mercer, told the New York Times.

That all seems simple, however, when you consider the complexity of figuring out who is eligible for no co-pay birth control - and who isn't. The rule also kicked in on Aug. 1, but could take months - if not years - for many insurance subscribers to gain access.

That's because the new regulation only kicks in at the start of a new insurance plan year.  A lot of employer-sponsored plans, for example, stick with the calendar year. For those plans, co-pays for contraceptives won’t go away until the start of 2013.

For some insurance subscribers, it many never take effect. There are a number of "grandfathered" health care plans that existed before the Affordable Care Act. As long as they don't make any big changes to their benefit packages, they do not have to adhere to a number of Affordable Care Act regulations - including the one that requires no co-pay contraception. Twenty-seven percent of the companies in the National Group on Business Health Survey reported having at least one grandfathered benefit option available in 2013.

The rules around the contraceptive coverage are so complex that Buzzfeed came up with this six-question guide to determining whether one has access. Usually, it involves calling an insurance company to find out.

The benefits that will roll out in the future are, of course, more significant, and difficult to miss. Americans will likely notice when they gain access to health insurance, for example. But even then, it's worth keeping in mind that we're talking about a minority of the population that will gain coverage: an expected 32 million, just about 10 percent of the population. There's another 24 million that will continue on without coverage.