There are many forms of compensation that typically account for supplemental wage payments. According to the IRS publication 15 (Circular E) on supplemental wages, supplemental wages include: Bonuses Overtime pay Awards Commissions Accumulated and unused sick leave Severance pay Vacation pay Tips Back pay Taxable fringe benefits Retroactive pay increases However, this is not an exhaustive list, and employers may choose to include additional forms of supplemental pay.