His breakthrough single, "Hurt Somebody", achieved gold status in the United States and charted in multiple international markets.

Within five years two more albums followed: I Was / I Am (2021) and Stick Season (2022), the second of which went on to be his mainstream commercial breakthrough and led to his nomination in 2023 for the Grammy Award for Best New Artist.

[4][9] Kahan cites some of his inspirations as being Paul Simon, Yusuf Islam (Cat Stevens), Counting Crows, Hozier, Sam Fender, Mumford & Sons, and Green Day.

In October 2020, Kahan began posting viral TikTok videos showcasing the first verse of what would become the hit single "Stick Season".

[13] The album debuted at number 14 on the Billboard 200, his first appearance on the chart[14] launching him into mainstream success and helping make him a recognizable figure within the music world.

[25] In April 2024, "Stick Season" hit a new peak on the Billboard Hot 100 at 9, the highest position of Kahan's career.

Kahan founded the Busyhead Project as an initiative to provide resources and information to Vermonters struggling with mental health issues.

Kahan performed a sold-out benefit concert that night having all proceeds going to Vermont-based mental health organizations.

[29] Kahan moved with his fiancée, Brenna Nolan, to Watertown, Massachusetts, part of Greater Boston, in July 2022.

[30][4][5] He writes music about his mental health; however, he is known to make light of his struggles with jokes on social media and in concert.

On his official TikTok account, Kahan admitted in a video that the only song of his that he listens to is "Maine", from his 2020 EP called Cape Elizabeth.