Athletes from South Korea and America will compete for medals at the Winter Olympics in Pyeongchang — but at least in one way, the South Koreans are already winning.

As recently as 1960, most South Koreans couldn’t expect to live past 55. Today, they can expect to live longer than Americans — for more than 80 years. And this gap is expected to get even wider very soon.

South Korea is billed to become the world leader in life expectancy by the end of the next decade. In a recent study, published in The Lancet, researchers predicted that average life expectancy in the country will reach beyond 90 years for South Korean women by 2030. Men there will also see big gains.

A handful of other wealthy countries will get closer to becoming centenarians too, but these improvements won’t be spread evenly. America, in particular, won’t be doing nearly as well against its economic peers. Instead, the US is poised to lag behind other wealthy countries when it comes to progress in longevity.

This South Korea-US contrast is yet another example of the importance of equitable access to health care — something South Korea and many other developed countries have managed to provide their citizens while the US continues to falter.

For the Lancet study, researchers at the Imperial College London, the World Health Organization, Northumbria University, and the University of Washington developed a new model for predicting future life expectancy in 35 countries using 21 forecasting projections. Most impressively, they found that in South Korea, life expectancy in women could jump from 84 in 2010 to 91 by 2030. In France, Japan, and Spain, female life expectancy is expected to hit at least 88 or 89 years, up from around 85.

Men in South Korea, as well as Australia and Switzerland, are also expected to lead the world in life expectancy, living to about 84 by 2030, with Canada, Spain, New Zealand, and the Netherlands following closely.

The US, by contrast, is among the countries in the study with the smallest boost, with similarly small gains in Japan, Sweden, Greece, Macedonia, and Serbia. In 2010, life expectancy for American men was 76, and for women, 81. In 2030, men here can expect to live to 79 and women 83 — increases of just a couple of years.

“Notable among poor-performing countries is the USA,” the researchers wrote, “whose life expectancy at birth is already lower than most other high-income countries, and is projected to fall further behind such that its 2030 life expectancy at birth might be similar to the Czech Republic for men, and Croatia and Mexico for women.”

And the prediction for the US may be too generous. The researchers only looked at data until 2013, so they didn’t account for the downturn in US life expectancy that has been happening since 2015 — the first such declines since the early 1990s. If the researchers updated their data to include that decrease, study author James Bennett said it’s likely they might have found an even lower life expectancy prediction for America.

The Lancet study is, of course, a modeling exercise, and unforeseen events, such as an epidemic or war, will affect the numbers. So would repealing Obamacare: Taking health insurance away from some 20 million Americans, and contribute to more deaths than gun homicides, HIV, and skin cancer.

The US–South Korea gap is astounding

As we’ve reported, there’s already a widening health disparity in the US — the outlier among rich nations in that it doesn’t offer its citizens universal health care. “This means that some groups are getting left behind and it’s pulling the average down,” said Bennett, a researcher in the department of epidemiology and biostatistics at Imperial College London.

The US has lagged behind its peers in increases in life expectancy (for both men and women) for at least a decade, despite gains from the 1970s to early 2000s. During that time, deaths from alcohol, drug use, and mental health disorders have risen dramatically in many parts of the country, while progress on heart disease has been stalling. (After peaking in 1985, heart disease deaths fell dramatically — but there has been an uptick since 2010, as you can see in this study.) The US also has some of the highest obesity, homicide, and infant and maternal mortality rates in the developed world.

If you use South Korea as a reference point, the contrast again is astounding. In 1960, the life expectancy for the average South Korean was only 53 years. But over the years, the country has made remarkable progress: South Koreans are now expected to live as long as 82 years — nearly four years longer than the average American.

The major reasons for the gains in South Korea — as in most rich countries — are reductions in infant mortality and cardiovascular diseases (particularly stroke), as well as declines in stomach cancers. These improvements were accompanied by rapid economic growth over the past 50 years, with gross national income per capita rising from less than US$100 in 1960 to $20,045 by 2007.

Bennett pointed out that “Korea got a lot of things right” when it comes to health care access, which is why the increases in longevity have been so widespread. “[South Korea] has had economic improvements, which has led to improved nutrition and access to health care and medical technology across the whole population,” he explained. Unlike the US, “South Korea is very equitable, all the way across the population,” he added.

That may be understating South Korea’s achievements. The country is viewed as an economic miracle. Once among the world’s poorest nations, it’s now one only two economies in the world (along with Taiwan) that have seen an annual average growth rate of more than 5 percent for five consecutive decades, as CNN’s Fareed Zakaria reported.

But what makes the South Korea example particularly striking is that on average, citizens in the US are far wealthier than South Koreans: The average income of Americans is $55,980 — more than double the average income in South Korea. For all its wealth over the past century, the US still hasn’t cracked health. And the growing problem of inequality here isn’t going to make things better.

Watch: The top reason people die early in each country