Updated October 18, 2026. Quick answer: Step 4 of Form W-4P holds the optional adjustments: other income you want withheld on, deductions that lower withholding, and extra tax per payment. Below it sit the No withholding box and the Step 5 signature line. Step 4(b) takes its number from line 17 of the Deductions Worksheet on page 4 of the form.
IRS worksheets read line by line: W-4P Deductions Worksheet.
What this part is for
Step 4 fine-tunes withholding on the Form W-4P certificate. The form’s purpose line is “Complete Form W-4P to have payers withhold the correct amount of federal income tax from your periodic pension, annuity (including commercial annuities)”. Like Step 3, steps 4(a) to 4(b) are subject to the multiple-payer rule: Complete Steps 3 to 4(b) “on this form only if (b)(i) is blank and this pension/annuity pays the most annually.” That rule is explained at Form W-4P Step 2.
The lines, one by one
| Line | What the form says |
|---|---|
| 4(a) | “Other income (not from jobs or pension/annuity payments). If you want tax withheld on other income you expect this year that won’t have withholding, enter the amount of other income here. This may include interest, taxable social security, and dividends” |
| 4(b) | “Use the Deductions Worksheet on page 4 to determine the amount of deductions you may claim, which will reduce your withholding.” “(If you skip this line, your withholding will be based on the standard deduction.)” |
| 4(c) | “Extra withholding. Enter any additional tax you want withheld from each payment” |
| No withholding box | “I request that no withholding be withheld from my payments.” “See Choosing not to have income tax withheld on” page 2. |
| Step 5 | “This form is not valid unless you sign it.” |
The instructions add detail for each line. For 4(a): “Enter in this step the total of your other estimated income for the year, if any.” “You shouldn’t include amounts from any job(s) or pension/annuity payments.” “If you complete Step 4(a), you likely won’t have to make estimated tax payments for that income.” The alternative is estimated tax: “If you prefer to pay estimated tax rather than having tax on other income withheld from your pension, see Form 1040-ES”. The Form 1040-ES guide covers it, and the retirement withholding calculator can help you size the withholding.
For 4(c): “Enter in this step any additional tax you want withheld from each payment.” “Entering an amount here will reduce your payments and will either increase your refund or reduce any amount of tax that you owe when you file your tax return.”
Where the number comes from
Step 4(b) is the only line with a separate worksheet. The instructions say “Enter in this step the amount from the Deductions Worksheet, line 17, if you expect to claim deductions other than the basic standard deduction on your 2026 tax return and want to reduce your withholding to account for these deductions.” “This includes itemized deductions, the additional standard deduction for those 65 and over”. The Deductions Worksheet is printed on page 4 of the form, together with its own limits and thresholds. Its figures are not reproduced here: read them on page 4 of your own copy of the form, and carry the result of line 17 to Step 4(b). The worksheet itself points to a further source: “See the Instructions for Schedule 1-A (Form 1040) for more information”. The 4(a) and 4(c) amounts are your own choices. See Form W-4P Step 3 for the line before this one.
Where it goes next
Below Step 4 are two choices the payer needs to see. If you want no withholding, the instructions say “You can choose not to have federal income tax withheld from your payments by checking the box in the No withholding section.” “Then, complete Steps 1(a), 1(b), and 5.” The instructions limit this: “Generally, if you are a U.S. citizen or a resident alien, you are not permitted to elect not to have federal income tax withheld on payments to be delivered outside the United States and its territories.”
The instructions caution about the consequence: “If you have too little tax withheld, you will generally owe tax when you file your tax return and may owe a penalty unless you make timely payments of estimated tax.” “If too much tax is withheld, you will generally be due a refund when you file your tax return.” “If your tax situation changes, or you chose not to have federal income tax withheld and you now want withholding, you should submit a new Form W-4P.”
Step 5 is the signature: “This form is not valid unless you sign it.” For how withheld tax is reported and claimed, see Form 1040 line 25. The step before this one is Form W-4P Step 1 and the sibling form for lump sums is Form W-4R lines 1a and 1b.
Figures from the step before
| Where | What the IRS prints |
|---|---|
| Step 3(a) | “Multiply the number of qualifying children under age 17 by $2,200” |
| Step 3(b) | “Multiply the number of other dependents by $500” |
| Periodic payments | “over a period of more than 1 year” |
Step 4 adjusts what Steps 2 and 3 set up. These are the printed amounts that Step 3 uses, shown here for reference; see Form W-4P Step 3.
Edition and line numbers
This page reads the 2026 version of Form W-4P, the current file irs.gov served on 2026-10-18. A payer may still be applying an earlier election; check the date and year printed on your own form. Use the line numbers and step letters printed on the copy you are holding, because a different edition can number or word them differently.
Common mistakes
- Using 4(a) for pension or job income. The instructions say “You shouldn’t include amounts from any job(s) or pension/annuity payments.”
- Checking the No withholding box without a plan for the tax. The caution says “If you have too little tax withheld, you will generally owe tax when you file your tax return and may owe a penalty”
- Forgetting to update the form when things change. The caution says “If your tax situation changes, or you chose not to have federal income tax withheld and you now want withholding, you should submit a new Form W-4P.”
Related: Form W-4P, Form 1040-ES, Form 1040 line 25, and retirement withholding calculator.
Sources
- Form W-4P (2026), Withholding Certificate for Periodic Pension or Annuity Payments: https://www.irs.gov/pub/irs-pdf/fw4p.pdf
- IRS: About Form W-4P: https://www.irs.gov/forms-pubs/about-form-w-4p
Read from the IRS documents linked above on October 18, 2026. General information, not tax advice. Your own facts decide the outcome, and a preparer, the account provider or the IRS is the right place to confirm anything consequential.