In August 2015, Mills released his second mixtape, titled
SubTrap. The name stands for Suburban
Trap or "trap music with substance". The album features the singles "The Plug," "God Said Trap (King Trappy III)", and "Cookie Addiction" featuring
BJ the Chicago Kid. It features production from
Skhye Hutch, was mixed by Lo Mein, Tim Webberson, Matt Weiss, and Delbert Bowers. Mills' style of rapping has been compared to the early work of
Kendrick Lamar, especially Lamar's 2011 album
Section.80. On June 24, 2016, Mills was announced as one of the performers at the 2016
Trillectro Music Festival. On September 9, 2016, Mills released his third mixtape
Empty Bank and premiered it on
Forbes. Mills opened for
Isaiah Rashad on his "The Lil Sunny" tour which started in January 2017. On October 13, 2017, Mills released his fourth mixtape
IWasVeryBad, which was released for free in collaboration with
Adult Swim. Mills later released the first six songs of the album as a series on
Noisey. This series gave the album visuals, and a new story. The first six songs were part of the first season, with the second season going unreleased, which assumingly would've included the last six songs. On November 9, 2018, Mills released his first EP
IDK & Friends :). On September 4, 2019, Mills released his debut
studio album,
Is He Real, including features from
Pusha T,
DMX,
JID,
Tyler, the Creator,
Burna Boy, and
GLC. On June 26, 2020, Mills released his second EP
IDK & Friends 2, which was used as the soundtrack for
Kevin Durant's
Basketball County documentary. On July 9, 2021, Mills released his second studio album,
USee4Yourself, including features from
Young Thug,
Offset,
Westside Gunn,
MF Doom,
Jay Electronica,
Lucky Daye,
SiR,
T-Pain,
The Neptunes,
Swae Lee,
Rico Nasty,
Slick Rick,
Sevyn Streeter, and more. On April 29, 2022, Mills opened for
Zedd at
Washington University in St. Louis as part of
WILD. On May 1, 2022, Mills performed at
Swarthmore College as part of Worthstock. On May 6, 2022, Mills released his third studio album,
Simple., which included features from
Denzel Curry and
Mike Dimes, and was executively produced by
Kaytranada. On May 5, 2023, Mills released his fourth studio album,
F65, including features from
Fat Trel,
NLE Choppa,
Jucee Froot,
Saucy Santana,
Tay Iwar,
Musiq Soulchild,
Rich The Kid,
Snoop Dogg and
Benny the Butcher. On 23 January 2026, he released his fifth mixtape,
E.T.D.S. under
Rhymesayers Entertainment, which received critical acclaim. Mills live performed a medley of the tracks "P.O" and "C.O.P", along with
Black Thought and Kaytranada, at
The Tonight Show Starring Jimmy Fallon on March 5. A music video for "C.O.P", directed by
Eric André, was released on April 7, 2026. == Discography ==