North Carolina and Maryland are both take part in the Drivers License Compact which requires its members to report back to the state in which a person is licensed violations that occur out of state.
The motor vehicle laws of NC allow for convictions occurring outside of North Carolina to be recorded on your driving record but points are assigned only for convictions occurring in North Carolina. If it is a serious traffic offenses that would result in a suspension or revocation in NC, than you may have these penalties in NC once they are notified of the out of state violation.
Even though points may not transfer or be assigned, if the MD speeding citation makes it onto your NCDOT driving record, than your insurance company may see it the next time they pull your MVR. At that point, depending upon your insurance provider's rating system; it could affect your insurance premiums.
If your insurance rates go up due to this speeding ticket or other reasons, you can get an affordable North Carolina car insurance quote here.