Deworming, how often should it be done?

We know deworming is important, but how often should it be done?

All pets need to be dewormed with a broad-spectrum dewormer regularly, even indoor pets that don't interact with other animals. Your pet should be dewormed every one to three months.

Puppies and kittens: Recommended at 6, 8, 10, 12 weeks and then monthly until 6 months old.
Mostly indoor: At least 4 times a year (every 3 months)
Indoor and outdoor: At least 4 times a year (every 3 months) or every month if in areas with heartworm or Spirocerca lupi (summer rainfall areas).
Mostly outdoor: Every month