A German court has ruled that Oskar Groening is fit to serve his sentence, which was handed down after a conviction for 300,000 counts of accessory to murder.
Groening was convicted of 300,000 counts of accessory to murder. His case could mark a precedent for future prosecutions.
Reinhold Hanning was found guilty of 170,000 counts of accessory to murder.
The 91-year-old German is said to have worked at Auschwitz for several months in 1944.
Oskar Groening said he is "truly sorry" for his role in the death camps.
Oskar Groening admits that "the events of Auschwitz, the mass murders, were known to me."
"On the question of whether I am guilty in legal terms, you must decide," Oskar Groening said.