If there’s one thing everyone can agree on about Obamacare, it’s that the law is complicated. Really complicated -- especially for a reporter trying to write about it on a deadline.

I’ve spent the past four years writing about the Affordable Care Act for two different newspapers. To this day, I still run into provisions that are new to me and face the challenge of trying to understand them fast enough to turn around a blog post later that day.

Unfortunately, covering the health law is unlikely to get easier anytime soon. As the new marketplaces roll out, and readers begin researching their options, they will no doubt have lots of questions about how it all works. Here are five of the common mistakes that I’ve made before, have seen others stumble on and hope you can avoid.

1. Not keeping the size of the overhaul in perspective. The Affordable Care Act is, without a doubt, the most significant insurance expansion since Medicaid and Medicare became law in 1965. At the same time, it will only impact a small sliver of the American population. Just 7 percent of the population -- or 24 million Americans -- are expected to use the health insurance marketplaces by 2023. An additional 13 million people will gain access to Medicaid through the health law’s expansion of the public program.

The vast majority of Americans will continue to get health insurance the same way they do right now, either through their employer or public insurance programs. When readers ask me how the health care law will affect them, and they currently have coverage through their employer, the answer can often be pretty simple: It won’t.

2. Comparing premiums from before and after the health care law. The health care law will dramatically upend the individual insurance market beginning Jan. 1. That makes comparing premiums from before the health law to those offered afterwards a bit like comparing apples to oranges -- or even apples to steak.

Here’s why: The health care law makes four big changes to the individual insurance market. First, it requires health insurance plans to cover all subscribers regardless of whether they have any pre-existing health conditions. This will likely increase premiums, as insurers will have to accept sick patients who, right now, they reject.

Second, it dramatically restricts the factors that insurance plans can use to determine the size of premiums that a subscriber will pay. Right now, they can use hundreds of different elements of an individual’s health. Starting in 2014, they can only use three factors: age, location and tobacco use. This change will likely increase premiums for the young and healthy, but decrease them for the old and sick.

Third, insurance companies are required to cover 10 categories of benefits, like maternity care and hospital visits. Known as the “essential health benefits,” this set of health care services is generally thought to be more robust than what individual market plans cover now. This policy will probably nudge up premiums just a bit.

Fourth and lastly, the health law includes subsidies for low- or middle-income people to purchase health insurance. This will likely decrease premiums, as it provides financial help for those buying their own coverage.

Taken together, these suite of four changes make the insurance market of tomorrow different than what exists right now. It’s one where insurers have to take all consumers -- and will have to provide a larger suite of benefits. Many shoppers will get financial help. This makes the market very different than what exists right now, and any comparisons between premiums of the past and future extremely difficult.

3. Just focusing on the premiums when other cost-sharing matters a lot for affordability. Premiums are an easy metric when it comes to judging health care costs. They are the most stable form of payment in a health plan, the one piece where the price stays the same from month-to-month. That probably explains why they’re most often used to examine how expensive a health plan would be for consumers.

Leaving out other forms of cost-sharing, though, doesn’t give consumers the full picture of what they might actually pay. When discussing health insurance costs, three other factors could help give readers a fuller picture. The first is the deductible, which is the amount consumers owe until their health plan begins to pay. In some cases, the deductibles on the exchanges are pretty high, upwards of $6,000 for an individual policy.

The second element that can help consumers understand the cost of their health plans is the co-payment, the fixed amount that the subscriber pays when they take a trip to the doctor. Lastly, there is co-insurance, when the subscriber pays a certain percentage of a the cost of a doctor trip.

These concepts don’t squeeze easily into a one-sentence comparisons of health insurance plans. But they do help readers get a better understanding of how much health insurance costs under the Affordable Care Act -- and helps them avoid the potential sticker shock of higher costs after committing to a certain premium.

4. Leaving out medical trends that pre-dated the Affordable Care Act. There are lots of changes happening in the healthcare industry, some of it due to the health law and some to completely independent factors. Tying everything to the health overhaul is easy to do, but also avoidable.

The best way to dodge this mistake is to look at how health care trends were evolving before the health care law took effect, and see if they have changed since. One great example in this space is the growth of health care costs, which has recently begun to slow. That could seem like a product of the health care law until you notice that the health cost slowdown began in 2009, while Congress was still debating whether to pass the Affordable Care Act. It’s helpful to do the same kind of research on premiums and narrow insurance networks, to get a sense of what began as part of the health law and what predated it.

5. Comparing the exchanges to “Expedia.” This is one area where, at least in my view, even the White House has been guilty of making a mistake. They’ve told voters that buying insurance on the new marketplaces will be just as easy as buying a plane ticket on Expedia.

But health insurance policies are more complicated than plane tickets, not to mention a much more significant financial commitment. We’re talking about a commitment to spend money each month. Telling readers that such a purchase will be as easy as shopping for a trip is most likely not true, even before all the technical problems the marketplaces are now experiencing.

Part of this has to do with the act of purchasing health insurance, which requires entering in information about your family size, your age and where you live. Part of it also has to do with how the federal government designed its website. Unlike most shopping websites, HealthCare.gov requires users to create an account before browsing insurance options. That has created what many technology experts see as a bottleneck that sometimes crashes the website, and makes the shopping experience more difficult than others.

Want to learn more? Sarah Kliff, who covers health policy for the Washington Post, will be our guest at noon Eastern on Wednesday through Poynter’s News University. Learn more and sign up now.

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