The 65-year-old actor gave an update Wednesday on Twitter after being hospitalized with the virus this week.
Schiff said he is no longer on oxygen and hopes to be released from the hospital soon. His wife, Sheila Kelley, who also has COVID-19, is improving at home.
"Covid update. I was just taken off Oxygen!! Markers are down. Cautiously optimistic for release soon. Perhaps all the prayers and thoughts need a big thank you," Schiff tweeted.
"@thesheilakelly also doing better. Let's keep sending positivity to everyone out there struggling. We got your back!" he said.
Schiff said Monday on Twitter that he was being treated with Remdesivir, oxygen and steroids for COVID-19 at the hospital.
"I am in the hospital on Remdesivir, O2 and steroids showing some improvement every day. Sheila is home and doing better but still fairly ill. Love you all," he wrote.
Schiff had announced last week that he and Kelley tested positive for COVID-19 Nov. 3 on Election Day.
"This has been the most bizarre week of our lives. @thesheilakelley is also positive. This is tough," he tweeted. "We are determined to find a way to health again. We root for everyone out there who are struggling with this thing."
Kelley later confirmed Gus, her son with Schiff, also has COVID-19.
Schiff and Kelley play Dr. Aaron Glassman and Debbie Wexler on the ABC series The Good Doctor. Schiff is also known for playing Toby Ziegler on The West Wing.