Justin Riley Eatmon was last seen at a home on Cloverdale Drive in Durham.
Officials said he arrived at Oak Grove Elementary School on Highway 98 in Durham Thursday morning.
The principal at Oak Grove Elementary School said Eatmon showed up to school on time after riding the bus to school.
"A lot of the teachers knew that he was missing from watching the news, and one of the teachers actually saw him in the cafeteria so they brought him to the office," Oak Grove Elementary principal Aisha Howard said.
Eatmon's foster mother came to the school Thursday morning to reunite with him after teachers found him unharmed.
Police said they will not file any charges in the case.
A Silver Alert was issued because Justin is believed be suffering from a cognitive impairment.