The vote was 5-4. The liberal bloc of Justices Ruth Bader Ginsburg, Sonia Sotomayor, Stephen Breyer and Elena Kagan noted their dissent.
Alabama Attorney General Steve Marshall had asked the Supreme Court to step in and allow those requirements to go back into effect after they were blocked by a lower court, which cited the coronavirus pandemic.
The state says the measures were enacted to protect absentee ballot fraud and pointed out that during the pandemic it has taken “extraordinary measures,” including issuing a state of emergency and entering a series of orders meant to protect health.
But four voters who are elderly or disabled joined with voting rights groups to challenge the requirements, arguing they violated the right to vote. They also challenged the state’s ban on curbside voting.
A lower court blocked the requirements in three counties — Jefferson, Mobile and Lee — for the July 14 Senate runoff.
Attorneys for the plaintiffs said they were “deeply disappointed” by the court’s decision.
“Unfortunately, this means that Alabama voters who are at greater risk of severe illness or death from COVID-19 will be required to risk their health and violate CDC recommendations in order to vote on July 14,” said Deuel Ross, senior counsel at the NAACP Legal Defense & Educational Fund Inc., in a statement.
“Litigation will continue and we intend to seek relief for our clients and other voters in time for November,” Ross added.
This story has been updated with additional information.
CNN’s Jamie Ehrlich and Paul LeBlanc contributed to this report.