[5] On January 27, 2016, Taeil released "Because of You" (단 한 사람) as a soundtrack for the TV series The Merchant: Gaekju 2015.

[9] As NCT U, Taeil, Taeyong and Doyoung released the song "Stay in My Life" on August 7, 2017, as a soundtrack for School 2017.

[15] On December 13, Taeil, Doyoung, Jaehyun and Haechan released the NCT U single "Coming Home", an SM Station collaboration with UNICEF.

[19] On June 28, the fourth part of the album, featuring "Morning Dew" sung by various artists including Taeil, was released.

[22] On October 11, Taeil, along with rapper Lil Boi, featured on Raiden's single "Love Right Back" from his debut EP of the same name.

[24][25] On December 27, SM Entertainment released the album 2021 Winter SMTOWN: SMCU Express, which includes the song "Ordinary Day", sung by Taeil and label mates Onew and Kyuhyun.

[36] On March 12, he released the single "Weird" (묘해, 너와), a remake of Acoustic Collabo's soundtrack from the 2014 TV series Discovery of Love.

[41] On August 15, 2023, Taeil was involved in a car accident in downtown Seoul while returning home by motorcycle after finishing his schedule early in the morning.

[42] On August 28, 2024, SM Entertainment abruptly announced that Taeil would be removed from the NCT line-up as a result of an investigation tying him to sexual offenses.

[46] On September 13, the Seoul Bangbae Police Station announced that the case had been handed over to prosecutors the previous day.