Actually in PA any trailer over 10K GVW requires the non commercial class A license upgrade, it’s fairly rare to find RV owners that comply with this from what I have seen and read.
Here is the actual PA wording.
Required to operate any combination of vehicles with a gross weight rating of 26,001 pounds or more, where the vehicle(s) being towed is/are in excess of 10,000 pounds. Example: Recreational Vehicle, when the towing vehicle is rated at 11,000 pounds and the vehicle towed is rated at 15,500 pounds (total combination weight of 26,500 pounds).
Trailer weight can be over 10,000 as long as the combination doesn't go over 26,000.
