Most people fill out a W-4 once, on their first day, and never look at it again. For 2026 that is a more expensive habit than usual. The IRS rebuilt the form to accommodate the One Big Beautiful Bill Act deductions, and the version sitting in your employer’s files almost certainly does not account for them. Here is what actually changed, and how to tell whether you should file a new one.
What actually changed on the form
The 2026 Form W-4 runs five pages, up from four, with three of them fillable. The headline change is the Deductions Worksheet that feeds Step 4(b). It moved onto its own page and expanded to 15 lines, and two of those lines are new:
- Line 1(a): an estimate of your qualified tip income
- Line 1(b): an estimate of your qualified overtime compensation
Those lines exist because the OBBBA deductions for tips and overtime are claimed at filing, not at the payroll level. Before the redesign there was no clean way to tell your employer “withhold less, because I expect a deduction that never shows up in my paycheck.” Now there is.
Three smaller changes matter too. Step 3 has clearer labeling for dependents and credits, and the child tax credit figure rose to $2,200 per qualifying child from $2,000. And claiming exemption from withholding is now a formal checkbox with a signed certification, replacing the old practice of writing “Exempt” in the margin.
The deductions those new lines are for
Worth being precise here, because the “no tax on tips” and “no tax on overtime” headlines oversold both.
Qualified tips: a deduction of up to $25,000, phasing out above $150,000 modified AGI ($300,000 filing jointly).
Qualified overtime: a deduction of up to $12,500, or $25,000 filing jointly. It phases out by $100 for every $1,000 of MAGI above $150,000 ($300,000 joint). It applies only to the premium half of FLSA-required overtime — the extra half in “time and a half,” not the whole overtime check. Married taxpayers must file jointly to claim it, and the return needs a valid Social Security number.
Both run through tax year 2028, and your employer reports qualified overtime separately in box 19 of your W-2.
Neither one is a payroll exemption. FICA still comes out at 6.2% for Social Security(up to the $184,500 wage base for 2026) and 1.45% for Medicare on every dollar of tips and overtime, and state income tax generally still applies. Our guide to how bonuses and overtime are actually taxed in 2026 covers that math in detail.
Who should actually file a new one
Filing a new W-4 is free and takes about ten minutes, but it is not urgent for everyone. Do it if:
- You earn meaningful tips or regular overtime and you are under the phaseout thresholds. This is the clearest case. If you are going to claim a $10,000 deduction at filing that your withholding knows nothing about, you are lending the government money interest-free all year.
- You got married or divorced, had a child, or picked up a second job. Multiple-job households are the most common source of underwithholding, because each employer withholds as though its paycheck is your only income.
- You owed a large balance last April, or got an unusually large refund. Both mean the withholding is miscalibrated.
- You are 65 or older, or you took out a qualifying auto loan — the OBBBA created deductions there too.
Leave it alone if your income is a straightforward salary, nothing has changed, and last April came out roughly even. A correct W-4 does not need annual maintenance.
How to fill in Step 4(b) without guessing
The worksheet walks you to the number. The mechanical version:
- Estimate your itemized deductions, if you itemize. If you do not, the 2026 standard deduction is $16,100 single, $32,200 married filing jointly, and $24,150 head of household.
- Add your above-the-line items, including the tips and overtime estimates on lines 1(a) and 1(b).
- The worksheet nets those against the standard deduction, and the result carries to Step 4(b).
Two cautions. Estimate tips and overtime conservatively and round down. Overtime is volatile — if you assume 400 hours and the schedule dries up in June, you have underwithheld and you will owe.
And if you work more than one job, use Step 2 properly. The Step 2(c) checkbox is the simplest option and works well when two jobs pay similarly. When they do not, the IRS Tax Withholding Estimator produces a better number than the checkbox does.
The penalty math, briefly
Underwithholding is not free, but the safe harbor is forgiving. You generally avoid an underpayment penalty by paying in at least 90% of what you owe for the year, or 100% of last year’s total tax — 110% if your prior-year AGI was over $150,000 — whichever is smaller. The prior-year number is the easier target, because you already know it.
Overwithholding carries no penalty, but it is not free either. A $3,000 refund is $250 a month you did not have.
Run it before you hand in the form
Adjust your gross pay, filing status and pre-tax deductions in the take-home pay calculator to see what a withholding change does to a single paycheck before payroll processes it.
DisclaimerThis article is general information, not tax advice. Tax rules are detailed and individual situations vary — confirm your eligibility, withholding decisions, and deduction amounts with a qualified tax professional before filing.