That's a question that doesn't have a right answer. I personally have never wormed my chickens ever, never will.
Others do it on a regular basis, which is not a good idea as worms will build resistance to wormers, and still others do it as they believe it's necessary. And lastly some do it after a veterinarian has checked a fecal sample.
You have to decide what is right for you and your situation, and your husbandry.