If the U.S. Supreme Court overturns Roe v. Wade, people seeking abortions in the South and Midwest would have to travel hundreds of miles to get an abortion, according to a new report released Thursday.

The Guttmacher Institute, a nonprofit research center based in New York and Washington that supports abortion rights, examined the impact of so-called trigger laws that would ban or severely restrict the procedure in multiple states if the high court issued such a ruling. It measured how far clients in those states would have to travel to get to the closest abortion clinic. It also looked at how states where the procedure would remain legal would be affected by the influx of patients.

“You’re talking about people in Texas and Mississippi traveling vast distances, not just trying to cross the border, but trying to go through multiple states in order to access care,” said Elizabeth Nash, the principal policy associate for state issues at the Guttmacher Institute. “The distances will take you days to access an abortion and return home.”

The Supreme Court is set to hear three abortion-related cases in the coming weeks. The justices will hear arguments Monday about whether the U.S. Justice Department has grounds to sue the state of Texas to block its new ban on abortions once cardiac activity is detected in the womb. In the other case, Mississippi has asked the court to overturn Roe v. Wade, and to uphold the state’s law that bans abortion after 15 weeks. (Under Roe, and the court’s subsequent decision in Planned Parenthood v. Casey, states cannot restrict abortion before a fetus is viable outside the womb, or at about 24 weeks.) Arguments in that case are scheduled for Dec. 1. Only the Mississippi case, however, is viewed by legal observers as having the potential to trigger new restrictions in other states.

Depending on the Supreme Court’s decision, about half of the United States could ban or impose more restrictions on abortion within the next year, according to the report. And most of the states are clustered in the South and Midwest, which would mean people there would have to travel hundreds of miles to get an abortion — escalating the procedure’s costs and overwhelming clinicians in states with fewer restrictions, who still have to serve their local populations.

The report explores three potential scenarios. First, what would happen if states could completely ban abortions? Second, what would happen if abortion was banned after 15 weeks of pregnancy, as Mississippi requests? Third, what would happen if it were banned 20 weeks into pregnancy?

From there, it divides the states into three categories based on their abortion laws — states that would be affected by a ban or additional limits on abortion, states that would feel relatively no impact, and states that would become “destination states” — places that people needing abortions would most likely go.

The Guttmacher Institute estimates that 26 states would be in the first category by completely banning or further limiting abortion. Of those states, 12 have “trigger laws” in place, while the rest have six-week bans or laws on the books from before the 1973 decision banning abortions that could be revived, according to the report. In five of the states, including Florida and Montana, lawmakers have taken actions in the past year that indicated they would probably ban abortion without the federal protections.

In the case of Mississippi, the closest clinic would be on average 495 miles away, the Guttmacher Institute said, probably in Illinois or North Carolina.

Destination states such as Kansas would also see sharp increases in the amount of people coming into the state to receive an abortion. Kansas could see 1,362 percent more people than usual — with about 5.2 million people specifically coming from Texas, according to Guttmacher’s analysis. Residents in neighboring states — Nebraska, Oklahoma and Missouri — would also probably find their closest clinic in Kansas.

The report only examines what could happen within the next year. But some of the states marked as destination states or no-impact states could change their laws, too. In Kansas, for examples, voters will decide in August whether to approve an amendment to the state constitution that would explicitly ban protections for abortion.

About 75 percent of abortion patients are low-income, Nash said. While there are organizations that put money aside to help cover the cost of an abortion — which on average is about $550, according to Nash — travel would incur more costs.

“By far, the most impacted by an abortion ban are not only low-income people, but people of color, young people and LGBTQ individuals because they have had the most burdens placed on them and the fewest resources with which to access health care,” Nash said. “You’re talking about a real failure.”