2017–2019: Grand Slam doubles debut, Top 500 debut in singles

Blumberg made his Grand Slam main draw debut at the 2017 US Open after receiving a wildcard for the doubles main draw with compatriot Spencer Papa.^[10]

He reached a career-high of World No. 438 in singles on February 18, 2019.

2021: Turned Pro, Maiden ATP title, Challenger tour success, Top 200

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. The unseeded pair reached the finals by defeating fellow Americans Tennys Sandgren and Denis Kudla, third seeds John-Patrick Smith and Harri Heliövaara, and second seeds Jonathan Erlich and Santiago González.^[11] In the final they defeated Austin Krajicek and Vasek Pospisil.^[12][13] With this run he entered the top 300 at World No. 284 on July 19, 2021, rising more than 1000 spots in the doubles rankings.

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. He followed that with a third Challenger win in Charlottesville in November also with Schnur.

2022: Major debut & win, Two titles, Top 100, US Open Mixed doubles semifinal

In January, Blumberg won his fourth Challenger title in Cleveland with 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.^[14]

At the 2022 Wimbledon Championships he made his debut at this Major partnering Casper Ruud.^[15][16] 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. They lost in the second round to Lloyd Glasspool and Harri Heliövaara.^[17]

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.^[18] At the same tournament as the defending champion in doubles, he reached the final partnering Steve Johnson.^[19] He would successfully defend his title with Johnson, defeating top seeds Raven Klaasen and Marcelo Melo in the final.^[20]

He reached the top 100 at World No. 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.^[21]

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.

He finished the season ranked No. 100 in doubles on 21 November 2022.

2023: French Open debut

He made his debut at the 2023 French Open partnering Miomir Kecmanović.

At the 2023 Wimbledon Championships he partnered again with Casper Ruud and reached the second round before withdrawing.

Doubles: 4 (3 titles, 1 runner-up)

Result	W–L	Date	Tournament	Tier	Surface	Partner	Opponents	Score
Win	1–0	Jul 2021	Hall of Fame Open, United States	250 Series	Grass	Jack Sock	Austin Krajicek Vasek Pospisil	6–2, 7–6(7–3)
Win	2–0	Jul 2022	Hall of Fame Open, United States (2)	250 Series	Grass	Steve Johnson	Raven Klaasen Marcelo Melo	6–4, 7–5
Win	3–0	Aug 2022	Los Cabos Open, Mexico	250 Series	Hard	Miomir Kecmanović	Raven Klaasen Marcelo Melo	6–0, 6–1
Loss	3–1	Jul 2023	Hall of Fame Open, United States	250 Series	Grass	Max Purcell	Nathaniel Lammons Jackson Withrow	3–6, 7–5, [5–10]

Doubles: 1 (1 runner-up)

Outcome	Year	Championship	Surface	Partner	Opponent	Score
Runner-up	2015	French Open	Clay	Tommy Paul	Álvaro López San Martín Jaume Munar	4–6, 2–6

Doubles: 10 (6–4)

Result	W–L	Date	Tournament	Tier	Surface	Partner	Opponents	Score
Loss	0–1	Jan 2014	USA F2, Sunrise	Futures	Clay	Frances Tiafoe	Jason Jung Evan King	7–6(7–4), 4–6, [6–10]
Win	1–1	Sep 2021	Cary, USA	Challenger	Hard	Max Schnur	Stefan Kozlov Peter Polansky	6–4, 1–6, [10–4]
Win	2–1	Oct 2021	Las Vegas, USA	Challenger	Hard	Max Schnur	Jason Jung Evan King	7–5, 6–7(5–7), [10–5]
Win	3–1	Nov 2021	Charlottesville, USA	Challenger	Hard (i)	Max Schnur	Treat Huey Frederik Nielsen	3–6, 6–1, [14–12]
Win	4–1	Jan 2022	Cleveland, USA	Challenger	Hard (i)	Max Schnur	Robert Galloway Jackson Withrow	6–3, 7–6(7–4)
Loss	4–2	Apr 2023	Tallahassee, USA	Challenger	Clay	Luis David Martínez	Federico Agustín Gómez Nicolás Kicker	6–7(2–7), 6–4, [11–13]
Win	5–2	Apr 2023	Savannah, USA	Challenger	Clay	Luis David Martínez	Federico Agustín Gómez Nicolás Kicker	6–1, 6–4
Win	6–2	Jun 2023	Modena, Italy	Challenger	Clay	Luis David Martínez	Roman Jebavý Vladyslav Manafov	6–4, 6–4
Loss	6–3	Sep 2023	Cary, USA	Challenger	Hard	Luis David Martínez	Andrew Harris Rinky Hijikata	4–6, 6–3, [6–10]
Loss	6–4	Oct 2023	Tiburon, USA	Challenger	Hard	Luis David Martínez	Luke Johnson Skander Mansouri	2–6, 3–6