Yes you do . 13,000 lb. GVWR requires a medical card .
Ram 3500 specs
Higher Gross Vehicle Weight Rating (GVWR): 13,000 pounds (Regular Cab, dual-rear-wheel axle with 6.7-liter diesel)
Towing: Up to 18,850 pounds (Regular Cab, dual-rear-wheel axle)
Payload: 6,650 pounds
Higher front...