Source: White House on Flickr

The Patient Protection and Affordable Care Act, better known as Obamacare, has inspired huge amounts of controversy since even before it became law. Proponents and opponents debated fiercely about the benefits and downsides of Obamacare, with many predicting unintended consequences that would surprise Americans. Yet even with the law having been in effect for a while now, a surprises keep coming up that few people on either side really expected to happen.

To keep you informed about Obamacare and its effects, we turned to three Motley Fool contributors for their views on the most surprising aspect of healthcare reform that largely escaped notice until now. Take a close look, and then let us know what you think about Obamacare's surprises in the comments section below.

Selena Maranjian: As Obamacare rolled out, many people didn't expect it to draw many enrollees, at least at first. And few expected that many of its myriad critics and opponents would come to embrace it. Obamacare has delivered plenty of surprises, though.

Consider its overall enrollment numbers. As of March, 16.4 million people had secured healthcare coverage via the ACA, whether signing up through a federal or state exchange, Medicaid expansion, or the ability to remain on parental plans longer. That caused the percentage of Americans without insurance to drop from 18% in 2013 to 12%. Those who thought the program wouldn't make a big dent in the number of uninsured were wrong.

Consider, too, the many people who were against the law, largely in "red" states. Large numbers of them have nevertheless been signing up for Obamacare. In North Carolina, as of early 2015, 43% of those eligible for coverage had signed up for it. In Kentucky's Floyd County region of Appalachia, the percentage of uninsured residents dropped from 19%  to 10% by the end of 2014, with half the population there now with government coverage. In Kansas and Missouri, enrollment jumped by close to 70% in the last enrollment period, with about 40% of potential enrollees in Kansas now covered and similar numbers in Missouri. About 40% of eligible Georgia residents and about a third of eligible folks in Wisconsin have also secured coverage.

Todd Campbell: When the Affordable Care Act was passed, many industry watchers, insurers, and consumers worried that the elimination of catastrophic health insurance plans would cause their premiums to soar, while also eliminating a valuable insurance option for healthy, young Americans.

Initially, an expansion of Medicaid to include families earning up to 138% of the Federal poverty rate was assumed to erase the need for catastrophic insurance plans for most people; however, a Supreme Court ruling that made Medicaid expansion an opt-in program resulted in many states taking a pass on that provision of the Act. As a result, many people in states like Florida and Texas fall into a coverage gap because they earn too much for Medicaid, but too little to qualify for subsidies through the Federal and state exchanges.

In an attempt to close that gap, catastrophic health insurance plans found renewed life as a fail-safe option for those under 30 and those who otherwise qualify for hardship exemptions.

Dan Caplinger: One surprising aspect of how Obamacare has played out is that the expected disappearance of Health Savings Accounts never actually happened. When the Affordable Care Act first became law, many believed that HSAs would no longer be viable because of the requirements that plans offer certain health benefits and have cover at least 60% of expected healthcare costs. At the time, that seemed incompatible with the high-deductible, low-premium nature of the health plans that qualified for use with HSAs.

As it turned out, though, many HSA-eligible plans have appeared on health insurance exchanges under Obamacare, making it possible for people to take advantage of the tax benefits of HSAs. By combining tax-deductible contributions with taking on more responsibility for the first layer of healthcare costs, HSAs offer incentives that many policymakers believe can contribute to lower overall spending on healthcare services and therefore help keep increases in the price of medical care under control.

Obamacare hasn't been ideal for HSAs, with the potential to get rid of some of the more complex and onerous regulations regarding eligibility for HSA treatment in favor of a simpler mechanism for people to participate. Nevertheless, the survival of HSAs is a positive for those seeking to control their own overall healthcare costs.