The road was closed between the B6349 Belford and B6348 Bellshill after the accident involving four vehicles in the Mousen Bends area at about 7.30am.
Police, ambulance and fire crews attended and three people were taken to hospital.
Local diversions were in place while the vehicles were recovered. The road was reopened after about two hours.
The A19 was also closed in both directions between the Holystone roundabout and Moor Farm roundabout this morning due to accidents in both carriageways involving several vehicles.
It has now reopened.
Earlier , Northumbria Police warned that road conditions across the force area were very difficult, due to black ice from the overnight wet weather and cold conditions this morning.
Police urged drivers to take care and said several accidents had already been reported.