Yes, the $15 monthly fee applies to a total of 20 contractors. I can provide additional details below, bill190.
The $15 per month fee for direct deposit covers up to 20 contractors, meaning it's the maximum number of people that you can send direct payments to. You won't need to pay for them separately as they are included in the plan. However, there is an additional cost of $2 per month for every extra contractor added for direct deposit.