Do I have to replace the toilet gasket if I remove the toilet?

Someone in my household flushed a pen down the toilet. It is stuck in there somewhere, either in the toilet or just past. It is creating problems. I figure I have to take the toilet off the floor and let the guilty party retrieve the pen. I’ve done a million home projects, but have never removed a toilet. My understanding is that there is a wax gasket below the toilet. My question is, when I remove the toilet, do I have to replace that gasket, or can I reuse it? If I don’t have to go to the store, I’d rather not.