The court said Ginsburg, 86, remained home because of a stomach bug. While not having the opportunity to question attorneys during the arguments, she will be involved in deciding the cases.
"Justice Ginsburg is unable to be present today. She is indisposed due to illness, but she will participate in the consideration and decision of the cases on the basis of the briefs and the transcripts or recordings of the oral arguments," Chief Justice John Roberts said from the bench.
Those cases are Comcast Corporation v. National Association of African American-Owned Media, et al., and Ritzen Group, Inc. v. Jackson Masonry, LLC.
Ginsburg has had two separate bouts with cancer in the past year. Her recovery from lung cancer surgery caused her to miss court sessions in January. They were her first absences from arguments in a quarter-century as a justice.
She had radiation treatment for a tumor on her pancreas in August.
After that treatment, Ginsburg later appeared at the National Book Festival in August, saying, "As this audience can see I am alive… and I’m on my way to being very well."
The Associated Press contributed to this report.