A document published by the Internal Revenue Service (IRS) that helps employers determine when they are to deposit Social Security, Medicare and income taxes for their employees. Employers must use one of the two authorized employment tax deposit schedules: semi-weekly or monthly. The deposit schedule used is based on the amount of tax liability reported during a lookback period, which is the calendar year preceding the previous year (e.g. the lookback period for 2011 begins in 2009).

Employers use the monthly deposit schedule if the total tax liability in the lookback year was $50,000 or less, and use the semi-monthly schedule if the total tax liability was over $50,000. For a new employer, the income for the lookback year is considered $0. Employers use Forms 941, 943, 944 or 945 when depositing funds.

The deposit instructions in IRS Publication 931 do not cover federal unemployment tax.