Study after study finds that the uninsured rate in the United States is at an all-time low, largely thanks to Obamacare’s insurance expansion.

Most Americans have no idea.

A new survey from the Kaiser Family Foundation finds that just 26 percent of Americans are aware that the uninsured rate in the United States is at an all-time low. Which means about three-quarters of the population doesn’t know that this incredible change is happening.

Democrats tend to be slightly more aware of the trend than Republicans, as are those who like Obamacare (those two groups likely overlap). But there is no group where the majority knows that the uninsured rate has fallen to an unprecedented level.

More surprising to me was the finding that one in five Americans think the uninsured rate is at an all-time high.

This isn’t really a knock on the American people, who have more going on in their lives than just learning about America’s uninsured rate. But it does indicate how hard it is for good news about the health care law to spread.

We ran a poll last year asking Americans whether they thought that the health care law had, so far, cost more than expected or less than expected, or whether they weren’t sure.

Only 5 percent got the right answer: that the health care law has come in under budget. Meanwhile, 42 percent estimated that the law had turned out to be more expensive than expected.

Media has a negativity bias — and this is one of the consequences

Findings like these aren’t specific to the health care law. There are studies finding that most Americans think the teen pregnancy rate is going up (it, too, is at an all-time low) or that crime is rising, when it’s actually dropping.

Part of this probably reflects how journalists like me cover the news, and a negativity bias we often display.

Take the example of rising insurance rates: I’ve written lots of stories about how the uninsured rate is falling and who is gaining coverage. But I’ve probably written just as many stories about the people who aren’t benefiting from the health care law.

Days before the Healthcare.gov launch in 2013, I wrote a lengthy story about the 31 million people who were not expected to gain coverage through the law. The Washington Post ran that story on the front page. I don’t think that was the wrong decision. As a journalist, I think it’s important to give voice to those who are in difficult situations and explain how that happened.

At the same time, it does create a type of news coverage that presents the current state of affairs as worse than it is — and that’s probably part of what’s going on with the current awareness of the uninsured rate.

If you’re interested in a more thorough discussion of negativity bias in the media, I definitely recommend listening to this recent episode of The Weeds, in which we discuss the subject at length.