The 15-year-old fan favorite has wowed the coaches all season.
The 15-year-old crooner from Shoreham, New York, delivered the final performance of the night on Monday's live semifinals show, and it was a doozy. Rubin made coach Gwen Stefani sob with his stunning performance of The Muppets' "Rainbow Connection."
"It was a really meaningful song for me, because Gwen was the one who picked it out for me," the young singer told reporters after the show. "She said that she wanted me to take this classic and make it my own, and that's what I tried my best to do."
"I dedicated this song to my brother, who's on the autism spectrum, because the song kind of reminds me of innocence, and just believing, and that's the way he lives," he added. "So I think it was a really nice dedication to him."
Whether he takes home the season 19 crown or not, Carter says his experience on The Voice has been "the time of my life" and he already feels like a winner.
"I've made so many new friends -- a lot of role models that I can look up to," he noted. "I made a partnership with Gwen, she's an incredible coach and incredible mentor. She gives the most amazing advice... I went in with an open mind, just wanting to soak up anything I could, and it's just been amazing."
"I'm just really, really blessed and lucky and thankful to be here. My family and friends are cheering me on from back home and that makes me really happy."
Though he's the season's youngest remaining competitor, Carter is already making big plans for his future, writing songs and looking forward to getting in the recording booth and performing concerts for his growing legion of fans.
As for an upcoming album, he said he hopes to emulate male singer-songwriters who have seen success on the pop charts in recent years, naming Lewis Capaldi, Harry Styles, Ed Sheeran and Shawn Mendes as some of the artists he admires.
"I love the music they put out there, and they've definitely inspired some of my songwriting," Carter said. "I want to go in the studio, record that and put it out for people to hear."