Nurse W-4 Guide 2026 — How to Fill It Out Correctly

Last updated: July 2026 | Reading time: 7 min

The IRS redesigned the W-4 in 2020 and many nurses are still submitting incorrect forms — resulting in either a large April tax bill or an unnecessarily large refund (which is just an interest-free loan to the IRS). For nurses with multiple jobs, travel assignments, or side income, the standard W-4 setup substantially underwitholds, setting you up for a surprise. Here's how to fill it out correctly for your specific situation.

W-4 Structure: What Each Step Does

Situation 1: Staff Nurse, One Job, No Side Income

This is the simplest case. Fill out Steps 1 and 5 (signature). Leave everything else blank. The standard withholding tables will work correctly for a single income source. If you're single with no dependents, you'll get a small refund or owe a small amount — that's normal.

Situation 2: Nurse With Two Jobs (Including Travel Contracts)

A travel nurse who works multiple contracts in a year — each with a different agency — has multiple W2 income sources. Each agency withholds as if their paycheck is your only income, systematically underwithholding because the combined income pushes you into a higher bracket.

The fix — Step 2: Use the IRS's Tax Withholding Estimator (irs.gov/W4App) to calculate the correct amount. The simplest approach: check the "Multiple Jobs or Spouse Works" box in Step 2c. This instructs the employer to withhold at the higher rate appropriate for dual income. You may slightly overwithhold (small refund) but you won't owe a large balance.

Alternatively: submit a new W-4 to your highest-paying employer with additional dollar withholding in Step 4c calculated based on the expected combined income's marginal bracket impact.

Situation 3: W2 Nurse With 1099 Side Income

This is the scenario where the most nurses get surprised at tax time. Your W2 employer withholds correctly for your hospital income. Your 1099 side income (consulting, per diem via 1099 agency, freelance medical writing) has zero withholding. You owe taxes on all of it, plus self-employment tax (15.3%).

The fix — Step 4c (Additional Withholding):

1. Estimate your annual 1099 income
2. Calculate the tax you'll owe: SE tax (15.3% of net) + income tax at your marginal rate (typically 22% or 24%)
3. Divide by the number of remaining paychecks in the year
4. Enter that dollar amount on Step 4c of your W-4

Example: You earn $30,000 in 1099 consulting income expected for the year. SE tax: $30,000 x 15.3% = $4,590. Federal income tax at 24% on net income: approximately $5,400. Total owed: ~$9,990. Divide by 26 biweekly paychecks remaining: $384/paycheck. Enter $384 in Step 4c.

This eliminates the need for quarterly estimated tax payments if you prefer the simplicity of single-source withholding.

Estimates assume 24% income tax bracket + 15.3% SE tax on net 1099 income. Actual amount depends on deductions and income level — use the IRS calculator for precision.

Situation 4: Travel Nurse Switching Between Agencies Mid-Year

Each new agency requires a new W-4. When you start a new travel contract, you submit a fresh W-4 to that agency. If you've already earned significant income with a prior agency this year, the new agency's default withholding doesn't account for income already earned at the higher agency. You're at risk of underwithholding in the new contract period.

The fix: When you start a new contract mid-year with a prior agency's income in the books, use the IRS withholding estimator (irs.gov/W4App), enter your year-to-date income, and calculate the appropriate withholding for the new W-4. Request extra withholding in Step 4c as needed to get your total withholding to the right level for the year.

Claiming Exempt: When It's Allowed (and When It's Not)

You can write "Exempt" on your W-4 (in Step 4c area) only if:

• You had zero tax liability in the prior year (owed no taxes and received a full refund), AND
• You expect zero tax liability in the current year

For most nurses with nursing income, this doesn't apply. Claiming exempt when you don't qualify is fraud — you'll owe the full tax plus penalties when you file. Don't do it based on advice that "you can get more money in each paycheck" — that money is not yours, and the IRS will collect it.

The Right Refund vs. Owe Mindset

Many nurses are taught to "aim for a big refund." That's a money myth. A large refund means you gave the IRS an interest-free loan all year. A large balance owed means you likely had an underpayment penalty. The optimal outcome is withholding within $500–$1,000 in either direction. Use the IRS withholding estimator in September/October of each year and adjust if needed — there's enough year left to correct course without under or overpaying significantly.

See also: Nurse Quarterly Tax Guide · Nurse Tax Deductions · 1099 vs W2 for Travel Nurses