Jacob McNeely, 17, had missed his bus home from school and a school staff member had driven him to his grandmother's home in the 4900 block of Englewood Drive, police said.
He was seen entering the house but his grandmother was not home.
When his grandmother arrived home later that day, she discovered the teen had left the house without his backpack, police said.
McNeely had been diagnosed with autism and his family told police they were concerned for his well-being.
This morning, San Jose police got a call from the victim's family reporting that McNeely had been found.
Family members said McNeely had walked into El Camino Hospital in Los Gatos at about 8:15 p.m. Tuesday, police said.
He was in good condition and has been reunited with his family.
Police said there is no indication of foul play in the teen's disappearance.