2020 Democrat presidential candidates continue to spar over whether to back the single-payer Medicare for All or a government public health option.

Here’s a primer on the differences between Medicare for All and a government public option.

Medicare for All

Medicare for All, most notably pushed by 2020 candidate Sen. Bernie Sanders (I-VT), would eliminate private health insurance and replace it with an expanded Medicare system that would cover all Americans and even illegal immigrants.

Sanders’ Medicare for All system most similarly mirrors the Canadian healthcare system, known as Medicare, in which doctors’ offices and hospitals remain private, but everyone obtains insurance through the federal government.

Medicare for All would offer every American universal coverage but even some Democrats such as Rep. Brad Schneider (D-IL) have expressed concern over how to pay for the proposal. Mercatus Center scholar Charles Blahous estimated that Medicare for All would cost $60 trillion over the next decade, $38 trillion of which amounts to new spending.

Sanders, Sens. Elizabeth Warren (D-MA), Kamala Harris (D-CA), Cory Booker (D-NJ), and other prominent 2020 candidates back Medicare for All.

Public Option

A public option would allow some, or all, Americans to choose a government health insurance plan, such as Medicare or Medicaid, while allowing private health insurance plans to compete against the public option.

A public option strikes a contrast with Medicare for All because the public option typically only allows coverage for certain populations, such as older or lower-income Americans.

For example, Sen. Debbie Stabenow’s (D-MI) public option bill would allow Americans older than 50 years old to purchase a Medicare plan.

The leftist Center for American Progress (CAP) would make the Medicare option available to anyone that wanted to sign up for a government health insurance plan.

Former Vice President Joe Biden’s public option plan would offer premium-free government health insurance for Americans who qualify for Medicaid if their state expanded the program under Obamacare, while former Rep. Beto O’Rourke’s (D-TX) plan would automatically enroll Americans without insurance in Medicare.

South Bend, Indiana, Mayor Pete Buttigieg said his ultimate goal is Medicare for All; however, he would like to start by offering a Medicare buy-in program that could outcompete private insurance.

“It will challenge private options to become more affordable and efficient,” Buttigieg wrote. “I am skeptical that they will be able to do so.”

As Democrats continue to decide who they will pick as their presidential nominee, a New York Times poll found that more presidential candidates favored a public option over Medicare for All.