We recommend deworming for puppies and kittens at age of 8 weeks, and repeat it again at 11 weeks.
If you are choosing to use a monthly heartworm, flea etc. combination-type spot-on or tablet product, you will be deworming your pet monthly that way.
It is very important to deworm all animals in the family at the same time, not just one, because a lot of parasites can spread from pet to pet.