[2] Promotions[citation needed] Andrzejczak began his military career as a platoon commander (2nd Infantry Regiment located in the city of Giżycko).

He also served as chief of staff (1998–1999) and as deputy commander (2001–2003) of the Lithuanian-Polish Peace Force Battalion (LITPOLBAT).

His next position was deputy chief the G-3 Operations Branch of the Land Forces Command.

Shortly after his return from foreign missions he was appointed as the deputy commander of the 34th Armoured Cavalry Brigade in Żagań (2008–2010).

Subsequently, he was moved to Cracow to 2nd Mechanised Corps, where he took the position of an assistant to the chief of staff (2010–2012).