"I have a client with a Standard Health FSA. It operates on a calendar year basis. However, the employer's payroll processes two weeks in arrears. Tax question as to whether the employer can deduct the final payroll from 2020 when the final payroll for 2020 is actually not paid out until the first payroll period in 2021. In other words, the work performed between December 15 and December 31 is paid on the January 15 payroll. That first payroll for 2021 is included as income for the 2021 W-2s -- not 2020. Has anyone dealt with this?"