The twice world champion left long-time coach Tutberidze to join Orser's team after she was upstaged by her training partner Alina Zagitova at the 2018 Pyeongchang Olympics.
Orser, a two-time Olympic silver medallist, coaches some of the world's top figure skaters, including Japan's double Olympic men's champion Yuzuru Hanyu.
The 20-year-old Medvedeva's return was warmly welcomed by Russia's figure skating community.
"I think this is a very correct and reasonable decision on the part of Zhenya," Maxim Trankov, a retired pairs skater who won Olympic gold in 2014, told RIA, referring to Medvedeva using the diminutive form of Evgenia.
"It's wonderful to see a great coach and a great athlete reunited." (Reporting by Gabrielle Tétrault-Farber; Editing by Pritha Sarkar)