During his brief appearance Zimmerman, looking thin and worn, said nothing.
The judge said the next court hearing will be May 29 at 1:30 p.m. ET and agreed with attorneys to seal the case records.
Zimmerman is charged with murder in the second degree for shooting Martin, who was unarmed.
Under Florida law, second degree murder refers to a killing that is not premeditated but is carried out with “a depraved mind regardless of human life.”
Zimmerman’s lawyer Mark O’Mara said his client will plead not guilty.