The case of David "Cole" Withrow - an honors student - has drawn national attention from gun rights groups who called it an example of what's wrong with gun control efforts.
Withrow told school administrators that he forgot the gun was in his locked truck in the school parking lot after a trip to go skeet shooting the weekend before.
Once he remembered the weapon, he used the phone in the school office to call his mom. Administrators overheard him, and he was arrested.
The statement released Tuesday by the law firm Hewett & Wood said Withrow lost an initial appeal and has decided against having his case heard before the school board.
"After a meeting with the school board attorney and some additional information being brought to our attention, we have decided not to any further appeals," read the statement.
The teen will finish his high school career at alternative school and will get a diploma. He said he's sorry for all the negative comments that have been directed at school officials since his arrest.
"Cole would like to apologize for all the stress and negative attention this matter has brought," read the statement.
The Withrow family said it does not agree with North Carolina law or Johnston County school policy, but believes school officials followed the rules.
The teen still faces a felony charge for bringing the weapon to school.
Withrow's future education appears to be taken care of. Liberty University Chancellor Jerry Falwell Jr. has offered the teen a full scholarship to the university.