He partnered as a wildcard pair with Jack Sock at the 2021 Hall of Fame Open in Newport, where he won his first ATP match.

He made his debut in the top 200 on November 1, 2021, after winning his first and second Challengers in Cary in September and Las Vegas in October with Max Schnur.

At the 2022 U.S. Men's Clay Court Championships, he reached the semifinals as a wildcard pair with Schnur where they lost to Ivan and Matej Sabanov.

[18][19] They defeated Miguel Ángel Reyes-Varela and Nicolás Barrientos in the first round in a five set match with a super tiebreak, his first win at a Major.

[20] At the 2022 Hall of Fame Open, he made his ATP main draw singles debut as a qualifier, losing in the first round to Benjamin Bonzi.

[22] He would successfully defend his title with Johnson, defeating top seeds Raven Klaasen and Marcelo Melo in the final.

85 on August 8, 2022, following his third title at the 2022 Los Cabos Open partnering Miomir Kecmanović, again defeating Klaasen and Melo in the final.

[24][25] At the US Open he reached the mixed doubles semifinals with Caty McNally on his debut at this event for the first time at a Grand Slam defeating en route defending champions Desirae Krawczyk and Neal Skupski in the second round.

[27] Blumberg partnered with John Peers at the 2024 U.S. Men's Clay Court Championships in Houston where they defeated the wildcard pair of Shelton and Andrés Andrade in straight sets, en route to his sixth final.