This week Republicans in Congress introduced a bill to repeal and replace the Affordable Care Act. Since then, debate in Washington has centered on the costs of the Republicans’ plan. But while money will move around if this plan is passed, it is really about life and death.

The core of the Republican plan is an end to a tax on investment income, a tax that has been used for the last seven years to pay for health insurance for about 20 million Americans (one in 12 of us).

No health insurance program — public or private — is perfect. But people who have health insurance are more likely to get the preventive care, screenings and medical care they need.

The Affordable Care Act has lengthened tens of thousands of lives. Before the act was signed into law, one in six Americans were uninsured. Now, only one person in 11 lacks insurance. With more than 20 million people gaining insurance, we saw real-life effects. The expansion of health coverage directly translated into reduced morbidity and mortality for Americans. Fewer Americans are sick, fewer are dying, and millions more are getting the dignity and care they deserve.

The Republican health care bill would roll back these gains, leading many Americans to lose coverage. We don’t yet know exactly how many, but we are talking here about millions of people. The Congressional Budget Office estimates that this bill would cause 14 million Americans to lose health coverage in the coming year, and 24 million to lose it over the coming decade.

But just how many people will lose their lives — not only their coverage — due to the proposed changes? That’s hard to estimate, but it’s going to be in the thousands, at least. Researchers at the Harvard School of Public Health studied mortality rate changes in Massachusetts after the rollout of the state’s health insurance platform in 2006. They found that overall the death rate from treatable illnesses declined by 4.5 percent. The decline in death was even greater in areas of the state where there were more low-income people who didn’t have health insurance before health reform. Harold Pollack, a University of Chicago professor, estimates that the Affordable Care Act saves around 24,000 lives per year. Let that number sink in for a moment.

Many Americans say that they want a new and better system. In fact, 58 percent of respondents to a Gallup poll favor replacing the Affordable Care Act — IF it’s replaced with “a federally funded health care program providing insurance for all Americans.”

Sen. Bernie Sanders proposed to do this, and it was wildly popular on the campaign trail. A Medicare-for-All program would save tens of thousands of lives by extending health insurance coverage to ALL Americans.

During the campaign, Donald Trump promised to repeal and replace Obamacare with something “terrific,” something that would cover “everybody.” This new proposal is opposite. In the service of cutting taxes for a few, it will shorten lives for many. America must reject it.