Box 1 of your W-2, labeled “Wages, Tips, Other Compensation,” is the single figure your employer reports as your pay that’s subject to federal income tax for the year. It combines everything taxable your employer paid you (regular wages, tips you reported, bonuses, commissions, severance, taxable fringe benefits, and certain stock compensation), then subtracts the pre-tax benefits you elected, like traditional 401(k) contributions and health premiums run through a cafeteria plan. The result is almost never the same as your salary, and it’s usually different from the wage figures in Boxes 3 and 5 right next to it.
What Gets Added Into Box 1
Federal law defines wages broadly: all pay for services you perform as an employee, no matter how it’s calculated or what the employer calls it.1Office of the Law Revision Counsel. 26 USC 3401 – Definitions That covers hourly pay, salary, overtime, commissions, and piecework. It also covers paid time off, because your employer is still paying you to be on the payroll.2eCFR. 26 CFR 31.3401(a)-1 – Wages Cash, check, direct deposit, and even property like stock all count.
Tips You Reported to Your Employer
All tips are taxable, whether cash, credit card, or shared through a tip pool.3Internal Revenue Service. Publication 531 (12/2024), Reporting Tip Income Tips you reported to your employer by the 10th of the month following the month you earned them flow into Box 1 because your employer withheld income tax on them.
Two limits are worth knowing. Tips from a single employer totaling less than $20 in any calendar month don’t have to be reported to that employer, though you still owe income tax and must include them on your return.4Internal Revenue Service. Tip Recordkeeping and Reporting Noncash tips like tickets or gift cards are reported on your return, not to your employer.5Internal Revenue Service. Tip Income Is Taxable and Must Be Reported
Bonuses, Commissions, Severance, and Back Pay
Bonuses and performance awards are fully taxable and appear in Box 1. So are advance commissions, severance pay, payments to cancel an employment contract, and back pay, including retroactive raises from union settlements and court-ordered awards.6Internal Revenue Service. Publication 525 (2025), Taxable and Nontaxable Income7Internal Revenue Service. Publication 957 (01/2024), Reporting Back Pay and Special Wage Payments to the Social Security Administration
Stock Compensation
Restricted stock units get added to Box 1 at their fair market value on the vesting or delivery date. Employers usually sell some of the shares automatically to cover withholding, which is why your brokerage may show fewer shares than the grant said.
Nonstatutory stock options work the same way at exercise: the difference between the stock’s fair market value and what you paid is compensation and lands in Box 1.8Internal Revenue Service. Topic No. 427, Stock Options That same spread also appears in Boxes 3 and 5, subject to the Social Security wage base cap.9Internal Revenue Service. Announcement 2002-108, Separate Reporting of Nonstatutory Stock Option Income
Taxable Fringe Benefits
Perks with real monetary value are taxable unless a specific exclusion applies. Common examples: the personal-use portion of a company car, and the imputed cost of employer-paid group-term life insurance coverage above $50,000, which flows into Box 1 and also appears in Box 12 with code C.10Internal Revenue Service. Group-Term Life Insurance
Moving expense reimbursements are taxable for civilian employees under the 2017 Tax Cuts and Jobs Act. The only exception is active-duty military moving under permanent change of station orders, who can still exclude reimbursements and deduct unreimbursed costs on Form 3903.11Internal Revenue Service. Instructions for Form 3903 (2025)
What Comes Out Before Box 1 Is Calculated
This is where most of the gap between your salary and Box 1 comes from. Several benefit elections are pulled out of your pay before your employer calculates the Box 1 figure.
Traditional 401(k) and 403(b) Contributions
Elective deferrals to a traditional 401(k) or 403(b) reduce Box 1 dollar for dollar. Defer $10,000 and Box 1 is $10,000 lower than your gross pay. Those same deferrals stay in Boxes 3 and 5 because Social Security and Medicare taxes still apply to them.12Internal Revenue Service. Topic No. 424, 401(k) Plans
Roth 401(k) and Roth 403(b) contributions behave the opposite way. Because they’re made with after-tax dollars, they don’t reduce Box 1 at all. The Roth amount is reported in Box 12 with code AA (Roth 401(k)) or BB (Roth 403(b)). If you’re contributing to a Roth account and wondering why Box 1 matches Boxes 3 and 5, that’s why.
Cafeteria Plan Health and FSA Elections
Premiums you pay for employer-sponsored health coverage through a Section 125 cafeteria plan come out of your pay before federal income tax, Social Security, and Medicare are calculated.13Office of the Law Revision Counsel. 26 USC 125 – Cafeteria Plans The same is true for contributions to a Health FSA or Dependent Care FSA run through the cafeteria plan. Because these reduce all three wage bases equally, they don’t create a mismatch among Boxes 1, 3, and 5.
Health Savings Accounts
Employer HSA contributions are excluded from Box 1 and reported in Box 12 with code W. For 2026, the combined employer-plus-employee annual limit is $4,400 for self-only coverage and $8,750 for family coverage.14Internal Revenue Service. Revenue Procedure 2025-19 Your own HSA contributions run through payroll under a cafeteria plan also come out of Box 1 before it’s calculated.
Education, Dependent Care, Adoption, and Basic Life
Several other benefits stay out of Box 1 up to statutory caps. Anything above the cap gets added back.
- Employer-provided educational assistance is excluded up to $5,250 per year.15Office of the Law Revision Counsel. 26 USC 127 – Educational Assistance Programs
- Dependent care assistance is excluded up to $7,500 for 2026 ($3,750 if married filing separately), an increase from the longstanding $5,000 limit.16Internal Revenue Service. Publication 15-B, Employer’s Tax Guide to Fringe Benefits
- Employer-paid group-term life insurance is excluded up to $50,000 of coverage; the imputed cost of anything above that goes into Box 1.10Internal Revenue Service. Group-Term Life Insurance
- Qualified adoption assistance is excluded up to $17,670 per child for 2026, subject to a higher-income phaseout.
Why Box 1 Doesn’t Match Boxes 3 and 5
Boxes 1, 3, and 5 measure three different tax bases, so they rarely produce the same number. Once you know which items are treated differently, the differences stop looking like errors.
The most common cause is a traditional 401(k) or 403(b) deferral. It comes out of Box 1 but stays in Boxes 3 and 5.12Internal Revenue Service. Topic No. 424, 401(k) Plans A $15,000 deferral pushes Boxes 3 and 5 roughly $15,000 above Box 1.
The Social Security wage base is the next big one. Social Security tax only applies up to an annual ceiling, which is $184,500 for 2026.17Social Security Administration. Social Security Tax Limits on Your Earnings Once your Social Security wages hit that cap, Box 3 stops climbing for the year while Box 1 and Box 5 keep going, because federal income tax and Medicare tax have no wage cap.18Internal Revenue Service. Topic No. 751, Social Security and Medicare Withholding Rates For high earners, Box 3 is often the smallest of the three.
How Box 1 Feeds Your Tax Return
The Box 1 amount from each W-2 goes on Line 1a of Form 1040.19Internal Revenue Service. Form 1040 (2025) If you had more than one employer during the year, add every Box 1 together. That combined figure becomes the wage piece of your gross income, which then combines with interest, dividends, capital gains, and other income, minus above-the-line adjustments like HSA contributions and educator expenses, to give you Adjusted Gross Income.20Internal Revenue Service. Definition of Adjusted Gross Income
The IRS gets its own copy of every W-2 and matches Box 1 to Line 1a automatically. If your reported number doesn’t line up with what your employer sent, expect a CP2000 notice proposing an adjustment and any extra tax the IRS thinks you owe.21Internal Revenue Service. Understanding Your CP2000 Series Notice The notice isn’t a bill, but ignoring it turns into one. Respond by the date on the notice.
If Your Box 1 Is Wrong
Errors do happen. A pre-tax benefit gets counted as taxable, a bonus posts twice, or stock that vested in late December gets left off. Start with payroll. Bring your pay stubs and your benefit elections. If they agree, your employer issues a Form W-2c along with a Form W-3c transmittal to the Social Security Administration.22Social Security Administration. Helpful Hints to Forms W-2c/W-3c Filing
If your employer won’t fix it or you can’t reach them and the end of February has passed, call the IRS at 800-829-1040. As a last resort you can file using Form 4852, a substitute W-2, estimating the correct figures from your records and explaining the steps you took to get the form fixed.23Internal Revenue Service. Form 4852, Substitute for Form W-2, Wage and Tax Statement Returns with Form 4852 attached take longer to process.
What Happens if You Leave Box 1 Income Off Your Return
The IRS already has the number, so a missing or understated Box 1 draws attention quickly. For unreported tips specifically, the penalty is 50% of the Social Security and Medicare taxes owed on the amount you failed to report to your employer, unless you can show reasonable cause.24Internal Revenue Service. Form 4137, Social Security and Medicare Tax on Unreported Tip Income For broader understatements, the accuracy-related penalty is 20% of the underpaid tax when the understatement is “substantial,” which generally means your reported tax was off by more than the greater of 10% or $5,000.25Office of the Law Revision Counsel. 26 USC 6662 – Imposition of Accuracy-Related Penalty on Underpayments The penalty rises to 40% for gross valuation misstatements or undisclosed foreign financial assets. Getting every Box 1 figure onto Line 1a is the cheapest way to stay out of that territory.