I switch when I need the coin types. like right now am on the search for more ATBs and almost out of nickels for lottery tickets, so getting a box of nickels to finish this month and a box of quarters next. might stay with quarters for a while and see how they do then go back to halves or maybe throw a box of dimes in there somewhere if I feel lucky. still tying to do pennies all the time though as I had 3 boxes to trade if and when a bank will.