He began his career in bureaucracy as the assistant for administrative affairs in the office of the Governor of North Sumatra and became the Regent of Central Tapanuli in 1980.

Although he lost the election, he was called to replace the seat of Raja Inal Siregar, who died after a plane crash.

After graduating from High School, Panjaitan continued his studies at the Law Faculty of the University of North Sumatra.

[2] After graduating, Panjaitan began to work in the office of the Governor of North Sumatra as the assistant for administration affairs.

During this period, Panjaitan enacted several policies, such as the Safari Martabe, the construction of the Dalihan Na Tolu institution, and unifying the split inside the Batak Christian Protestant Church.

The Martabe movement (abbreviation of Marsipature Hutana Be, literally Building Your Own Village) was first delivered in a speech by the Governor of North Sumatra, Raja Inal Siregar, in Sipirok on 24 December 1988.

Numerous government officials and villagers from North Tapanuli were brought to Jakarta as part of the Safari Martabe.

[14] His chance as the interim replacement came when two members of the Regional Representative Council from North Sumatra, Abdul Halim Harahap and Raja Inal Siregar, died in the Mandala Airlines Flight 091.

In accordance to the law, if any Regional Representative Council members who have been inaugurated have either resigned or died, then the rank below him became the substitute.

[18] At the 2019 Indonesian general election, Panjaitan was appointed as the member of the board of the director of the Joko Widodo 2019 presidential campaign team's branch in North Sumatra.