What determines my monthly costs for a company LPFSA?

As an employer, your monthly costs are based on the number of "seats", which is the maximum number of employees who were enrolled at any time. 

• When your plan starts, Zenefits uses the number of employees who enroll at the start of the plan to determine the initial number of seats and your first monthly payment's amount. 
• If other employees enroll later in the year, Zenefits will increase the number of seats, and charge for the additional ones. 

If employees who were enrolled leave your company (and cancel their FSAs), Zenefits won't refund you for those employees. However, for every seat vacated by an employee, another employee can enroll at no additional cost to you.