Bean bag chairs have many different types of fill and this will determine how often the insides need to be replaced. Traditional bean fill can break down over time and you might want to top up the bean components every year. You don’t have to remover the old beans; however, over time this will add to the overall weight of your chair. After a few years you might want to get rid of the entire inside components and start with fresh bean fill.
Foam, on the other hand, will last for a lot longer. You might need to add more in one or two years, but foam is meant to fluff back to its original size. A few fluffs each day should keep the foam nice and bouncy.