He has since had leading roles in Beating Again (2015), One More Happy Ending (2016), Missing Nine (2017), Prison Playbook (2017–2018), Life on Mars (2018), When the Devil Calls Your Name (2019), Hospital Playlist (2020–2021) and Crash Course in Romance (2023).

Jung's first major break came in 2004 melodrama series I'm Sorry, I Love You, playing the supporting role of an actor who belatedly falls for his childhood friend (Im Soo-jung) and has an unusually close relationship with his mother.

[7][8] It was a critical and commercial hit, which led to his being cast in two films in 2005: he played the pop singer crush of a novice nun (Yoon Jin-seo) in the ensemble romantic comedy All for Love,[9] and the more proactive assistant of a shy photographer (Kim Joo-hyuk) in When Romance Meets Destiny.

[15] Director Lee Joon-ik then cast Jung in Sunny (2008) as a double bassist in a "consolatory band" who helps the heroine (Soo Ae) find her husband during the Vietnam War.

[18] After Ja Myung Go's lackluster ratings, Jung bounced back with popular family drama Smile, You, in which he and Lee Min-jung stars as a couple from different backgrounds.

"[19][20] After that, Jung chose the low-key The Great Gye Choon-bin (2010), a one-act Drama Special episode where he played an art therapist who meets a quirky kindergarten teacher who helps him get over his fear of the dark.

[32] Jung played a single father who worked as reporter-photographer of gossip magazine "Masspunch", Song Soo-hyuk, love interest of main lead Han Mi-mo, acted by Jang Na-ra.

In 2017, Jung starred in disaster drama Missing Nine,[33] followed by the critically acclaimed Shin Won-ho's black comedy series Prison Playbook.

In 2020, Jung reunited with director Shin Won-ho in hit and critically acclaimed medical drama Hospital Playlist as Kim Jun-wan, an associate professor of cardiothoracic surgery who became chief of the CS department later on.

[43] On August 24, 2021, it was announced that Jung, Jo Jung-suk, Jeon Mi-do, Yoo Yeon-seok, and Kim Dae-myung will start filming Na Yeong-seok's new variety show in Gangwon Province on September 6.

[45] He reprised his role as Prior Walter in The National Theater Company of Korea's premiere of Angels in America - Part Two: Perestroika.

[54] In April 2008, he and actor Yoo Ha-jun became business partners and launched the internet shopping mall Double Bill,[55] which sold vintage and trendy clothes for men.