Here's the definitive answer. ANY, yes ANY trailer that the gross weigh is over 10,001 lbs., The driver NEEDS (per DOT rules) an "A" class license PERIOD. 5th wheel or tag, there's no difference. There is a "modified A" license that allows you to tow up to 26,000 lbs. Before you all jump on me, I have been on the road for 40+ yrs. The DOT only is interested in COMMERCIAL vehicles. That's why landscapers have been singled out. The regular state police worry about the rest even though they will enforce the DOT laws. Usually they have better things to do and don't mess with private trailers. Now I'm not saying that they never mess with ya but not normally.