You can see all of the requirements at usscouts.org: http://usscouts.org/advancementTOC.asp

I just went and looked at all the academic beltloops and all of them had the same requirements regardless of age/rank, which is what I was pretty sure was the case. That to me is one of the upsides of the program, beltloops and other awards like Crime Prevention, Emergency Preparedness, Donor Awareness and the 2010 Award ribbons – that the requirements are the same throughout all age levels. That makes them great for planning things to do at Pack Meeting, campouts and other events where boys from all age levels will be present. It allows them all to work together and for the younger kids to get some interaction with the older boys (and vice versa).

Back to the more specific point of the Original Poster's question though, I was thinking further about the whole idea that beltloops should be removed at the end of the year and that just seems kind of unsettling to me. Talking about earning the beltloop multiple times is kind of besides the point which was about if it says somewhere that boys should take off all beltloops earned at the end of the program year. I cannot think of many instances where a boy is required to remove an award from his uniform. Obviously there are some – when a Cub Scout gets his Webelos badge and either has to remove the diamond Tiger rank to put on the diamond Webelos rank or remove all the diamond rank badges to put on the oval Webelos badge; the progress towards ranks totem for Wolves/Bears comes off the uniform after he receives his Bear rank and moves on to Webelos and likewise the Tiger Totem comes off when the boy moves on to Wolves; the previous rank badge is removed and replaced at the Boy Scout level when he earns the next rank – but in all these instances it isn't so much about removing what was earned as it is about replacing it with the next step. The progress towards rank totem isn't needed anymore after the ranks have been earned, he has a Wolf and Bear badge on his chest to signify that. Same with the Webelos patch or the Boy Scout rank patches.

To me, having the boys take beltloops off their uniform at the end of each program year seems to be counter to the Advancement & Recognition method of the BSA in general. The Cub Scout belt (and the beltloops that go on that belt) are a permanent part of the official Cub Scout uniform. It just doesn't make sense to have them remove an award from their uniform if they haven't earned something else that replaces the one they have.

Our pack's policy has always been that the pack covers rank items (rank badges, totems/beads, activity badges and arrow points). All else is paid for by the family. The first time a Scout earns a beltloop or pin, we automatically get him one and the Scout's ISA is charged. After the first time, we don't pick up that beltloop or pin again if a Scout re-earns them unless the family specifically requests us to do so. It has worked out pretty well in our pack.