The allegations against the accused, identified by daily newspaper Die Welt as Bruno Dey from Hamburg, concern atrocities committed at the Stutthof concentration camp, near what was then Danzig, now Gdansk in Poland.
He worked between August 1944 and April 1945 at the camp, which ended up holding 110,000 prisoners, 65,000 of whom perished.
Despite his senior age, the accused will be tried by a juvenile court in Hamburg, because he was 17 when he first worked at Stutthof.
Prosecutors accuse him of having contributed to the implementation of the Nazis' order to kill as a “cog of the murder machinery”.
According to Die Welt, Dey was questioned by Hamburg prosecutors last year and he does not deny his presence in the camp, which was part of the Nazis' vast network of concentration camps.
The trained baker reportedly insisted he was never a Nazi and only ended up in the SS-Totenkopfsturmbahn (Death's Head Battalion), which ran the camp, because of a heart disease.
According to the report, Dey confirmed he had guard duties at the watchtowers and knew of the camp's gas chambers, where he saw SS prisoners being pushed inside.
He admitted seeing “emaciated figures, people who had suffered”, but insists he is not guilty, replying “what use would it have done? They would have just found someone else” when asked why he did not put in a transfer to fight at the front, Die Welt reported.
The case is likely to be one of the last trials involving Nazi war crimes.
Earlier this month, a German judge suspended the trial of a former concentration camp guard, who also worked at Stutthof, after the 95-year-old defendant was hospitalised with heart and kidney problems.
Germany has been racing to put on trial surviving SS personnel, after the legal basis for prosecuting former Nazis changed in 2011 with the landmark conviction of former guard John Demjanjuk.
He was sentenced on the grounds that he served as a cog in the Nazi killing machine at the Sobibor camp in occupied Poland, rather than for murders or atrocities linked to him personally.
The Nazis had initially used Stutthof as a detention camp for Polish prisoners but later also transported Jewish detainees to the site.