He won a complete set of medals in the four-man event at the FIBT World Championships with a gold in 1951, a silver in 1954, and a bronze (tied with Sweden) in 1953.

Pössinger finished sixth in the four-man event at the 1956 Winter Olympics in Cortina d'Ampezzo.

Michael Pössinger joined the mountain troops of the Wehrmacht in October 1937, and took part in the Invasion of Poland (1939) and the Battle of France (1940).

[1] In 1941 Pössinger participated in the FIS Alpine World Ski Championships 1941 at Cortina d'Ampezzo in Italy and won a Silver Medal.

Historian Hermann Frank Meyer assumes that the actions were personally led by Pössinger.