LORs and Gap Years for MSW

After I complete my undergrad, my plan is to obtain an MSW.

For personal and professional reasons, I will most likely take 2+ years after I finish my BA to work and gain field experience. When it comes to LORs, schools like UC Berkeley require an academic LOR. What do I do about that? Do I ask my professor to write a LOR and then hold on to it until I apply?

Talk with your professors this year. Find out which of them feel that they can write good LORs. Stay in touch with them after graduation. Then when you are ready to apply to grad school it will be more likely that they will remember who you are.