Deposit schedule lookback.

How the lookback works

Pub. 15 says a Form 941 filer’s deposit schedule for a calendar year comes from the total taxes reported on Forms 941, line 12, over a four-quarter lookback period that begins July 1 and ends June 30. For 2026 that is July 1, 2024 through June 30, 2025. A Form 943 or Form 944 filer for the current year or either of the two preceding years uses the total reported for the second preceding calendar year, so the lookback period for 2026 is calendar year 2024. Form 945 filers use line 3 of their Form 945 for that same second preceding year. If a 2026 Form 941 filer filed Form 944 in 2024 or 2025, the lookback period is calendar 2024.

What each schedule means

Semiweekly depositors must complete Schedule B (Form 941), Report of Tax Liability for Semiweekly Schedule Depositors, and submit it with Form 941. A deposit due on a day that is not a business day is on time if made by the close of the next business day, and a semiweekly depositor has at least 3 business days after the close of the semiweekly period.

Details that catch people

• New employers. For a Form 941 filer, tax liability for any lookback quarter before the business started is treated as zero, so you are a monthly depositor for the first calendar year. For Form 943, 944 and 945 filers that rule covers the first and second calendar years.
• Corrections do not move you. Adjustments on Forms 941-X, 943-X, 944-X and 945-X do not change the lookback liability. Pub. 15’s example: an employer originally reported $45,000, later found a $10,000 understatement and filed Form 941-X, and is still a monthly depositor for 2026 because the original amounts were $50,000 or less.
• $100,000 next-day rule. If you accumulate $100,000 or more in taxes on any day in a monthly or semiweekly deposit period, you must deposit by the next business day, whichever schedule you are on.

Worked example

Pub. 15’s own example uses Rose Co. Its Form 941 taxes were $12,000 in each of the third and fourth quarters of 2024 and the first quarter of 2025, and $15,000 in the second quarter of 2025: $51,000 for the 2026 lookback period. That is more than $50,000, so Rose Co. is a semiweekly depositor for 2026. For 2025 its lookback total (third quarter 2023 through second quarter 2024) was $48,000, so it was monthly. Annual filers should also read the Form 944 eligibility page.

Limits of this tool

This applies only the $50,000 test to figures you supply. It does not check whether you are a new employer, whether you hit the $100,000 rule, or whether you can pay with your return under the $2,500 exception; those rules are in section 11 of Pub. 15.

Sources

• Publication 15 (2026), Employer’s Tax Guide, section 11: Lookback period and Table 1, monthly and semiweekly deposit schedules, new employers, adjustments, the $100,000 next-day deposit rule and the Rose Co. example. Read November 2, 2026.

IRS page last reviewed April 30, 2026. Figures follow Publication 15 (2026).