The Affordable Care Act (often known as Obamacare or the ACA) passed a milestone recently: it’s been five years since it was signed into law.

It went into effect last year, and even five years later, the ACA is still being debated in settings ranging from the water cooler to the editorial page to the Supreme Court.

It’s not hard to understand why people have such strong feelings about the Act. Access to health care is crucial to quality of life, and paying for health insurance is a major line item on the budgets of families and corporations alike. Since March 2010 when the Act passed (and even before then when it was being discussed), I have been fielding questions at virtually every speech and meeting about it. While a full debate of the pros and cons and potential outcomes is impossible within the word count I am allowed, I do want to take a step back and point out a few key things.

One of the most controversial aspects of the ACA has been its costs to the federal government. Baseline estimates of the cost of the ACA’s insurance coverage provisions have been changed many times since the law was enacted in March 2010 (they’ve been going up), and this pattern has raised concerns among many that costs are spiraling out of control. It is important to note, however, as pointed out in a recent update from the Congressional Budget Office (CBO), that projected costs have been given over the subsequent ten years, so the period spanned by the estimates has changed. Because health care costs have been rising, each time the projection period changes, a less expensive early year is replaced by a more expensive later year.

If you compare year by year, however, CBO estimates of the net budgetary impact of the ACA’s insurance coverage provisions have decreased. For example, in March 2010, insurance-related provisions of the ACA were projected to cost the federal government $710 billion over the 2015-2019 period. The most recent projections peg costs at $506 billion for that same period. There are multiple reasons for this decrease, including changes in law, the recession, the Supreme Court’s decision to allow states to choose whether to expand eligibility for Medicaid, administrative actions, and the availability of new data. In addition, the rate of growth of health care costs has slowed, though the recent recession is part of the reason for that pattern.

The bottom line is that there are a lot of moving parts in determining the costs of the ACA and how they are changing. Depending on the data source and other factors, it is possible to paint an optimistic or pessimistic picture, which only fuels the controversy. As with most interpretation of statistics, it is important to take a good look at exactly what is being measured and reported.

In addition to cost, there are other aspects of the law that cause it to be divisive. A recent analysis from the Kaiser Family Foundation found that those who view the ACA favorably say they like it because it will expand access to health care and health insurance, make health care more affordable, and make Americans and the United States better off in general. Those who do not like it mention financial considerations (such as costs of health insurance and health care as well as the cost of the law), opposition to the individual mandate, and concerns about government overreach.

Despite these widely divergent views of the ACA, the gap between those who view the ACA favorably and those who see it unfavorably have narrowed over the past few months. In March, 43 percent of those surveyed by the Kaiser Family Foundation indicated they had a generally unfavorable view of the law, while 41 percent said their opinion was generally favorable. Last summer, the results were 53 percent unfavorable and 37 percent favorable. While the gap is smaller than it was a few months ago, it remains persistent. In addition, the fact that opinion is divided about down the middle between those who like ACA and those who don’t illustrates just how divisive the law has been. There is no question that more people having access to health care is a good thing, but there are many questions about the best way to get there.

Editor’s Note: The main picture with this story shows Rio Grande Valley residents signing up for the Affordable Care Act at the McAllen Convention Center in March, 2014. (Photo: RGG/Raul de la Cruz)