Total Income on a W-2: Box 1 vs. Boxes 3, 5, and 12

The number most people mean by total income on a W-2 is in Box 1, labeled “Wages, tips, other compensation.” That is the figure that flows to line 1 of your Form 1040 and the amount the IRS treats as your federal taxable wages for the year. It is almost never the same as your gross salary, and it is almost never the same as the two wage figures sitting right next to it in Boxes 3 and 5.

What Box 1 Actually Shows

Box 1 starts with your gross pay for the year — salary, hourly wages, commissions, bonuses, and taxable fringe benefits — and then your employer subtracts the pre-tax items that federal income tax does not reach.

The two biggest subtractions are retirement deferrals and health-related benefits. Traditional 401(k) contributions come out of Box 1 because they are not subject to federal income tax in the year you earn them.1Internal Revenue Service. Are Retirement Plan Contributions Subject to Withholding for FICA, Medicare, or Federal Income Tax The same treatment applies to 403(b) and governmental 457(b) deferrals. Premiums for employer-sponsored health insurance, flexible spending account elections, and HSA contributions made through a cafeteria plan are also excluded.2Office of the Law Revision Counsel. 26 USC 125 – Cafeteria Plans

A few items get added back in. If your employer provides group-term life insurance above $50,000 of coverage, the cost of the excess is taxable and lands in Box 1.3IRS.gov. Group Term Life Insurance After all of that, Box 1 is usually the smallest of the three main wage figures on the form.

Why Boxes 3 and 5 Show Different Numbers

Boxes 3 and 5 report the wages used to calculate your share of FICA. Box 3 is your Social Security wages; Box 5 is your Medicare wages. They follow different rules than Box 1, and that is why they typically come out higher.

The main reason: traditional 401(k) and similar retirement deferrals are excluded from Box 1 but stay in Boxes 3 and 5. Retirement contributions dodge federal income tax, but Social Security and Medicare tax still apply.1Internal Revenue Service. Are Retirement Plan Contributions Subject to Withholding for FICA, Medicare, or Federal Income Tax Cafeteria plan benefits like health premiums, FSA contributions, and HSA contributions run through payroll are excluded from all three boxes because they are exempt from both income tax and FICA.4Internal Revenue Service. FAQs for Government Entities Regarding Cafeteria Plans

Box 3 has a ceiling. Social Security wages are capped at the wage base, which is $184,500 for 2026. Once you hit that amount, Box 3 stops. The tax rate is 6.2% up to the cap, so the maximum Social Security tax an employee can pay in 2026 is $11,439.5Social Security Administration. Contribution and Benefit Base

Box 5 has no cap. Medicare tax applies to every dollar of covered wages at 1.45%.6Internal Revenue Service. Topic No. 751, Social Security and Medicare Withholding Rates An additional 0.9% Medicare tax applies once wages cross a threshold that depends on filing status: $200,000 for most filers, $250,000 for married filing jointly, and $125,000 for married filing separately. Employers must begin withholding the extra 0.9% once your wages with them pass $200,000 in a calendar year, regardless of your filing status.7Internal Revenue Service. Topic No. 560, Additional Medicare Tax That is why Box 5 is usually the largest number on a high earner’s W-2.

A Worked Example

Say you earned $80,000 in gross salary in 2026, contributed $6,000 to a traditional 401(k), and paid $3,000 in health insurance premiums through your employer’s cafeteria plan. The wage boxes would look roughly like this:

  • Box 1: $80,000 minus the $6,000 401(k) deferral and the $3,000 in health premiums, for $71,000 of federal taxable wages.
  • Box 3: $80,000 minus just the $3,000 in health premiums, for $77,000. The 401(k) deferral stays in because it is still subject to Social Security tax.
  • Box 5: Also $77,000 in this case, because the earner is well below the Social Security wage base.

For someone paid above $184,500, Box 3 would freeze at the cap while Box 5 kept climbing with each additional dollar.

Box 12: The Codes That Explain the Gaps

Box 12 itemizes the specific items that created the differences between Boxes 1, 3, and 5. Each entry pairs a letter code with a dollar amount. The retirement codes are the ones that most often explain a Box 1 that looks lower than gross pay:

For 2026, the elective deferral limit for 401(k), 403(b), and most 457(b) plans is $24,500. Workers age 50 and older can add an $8,000 catch-up, and those aged 60 through 63 get a higher catch-up of $11,250.9Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500

Two health-related codes also show up often:

  • Code W: Total HSA contributions made through payroll, including both employer and employee amounts. Excluded from Boxes 1, 3, and 5 when made through a cafeteria plan. The 2026 HSA limit is $4,400 for self-only coverage and $8,750 for family coverage.10Internal Revenue Service. 2026 General Instructions for Forms W-2 and W-311Internal Revenue Service. Rev. Proc. 2025-19
  • Code DD: The total cost of employer-sponsored health coverage. This figure often looks alarming and can be $15,000 or more, but it is purely informational. It is not taxable income and does not affect any wage box.12Internal Revenue Service. Form W-2 Reporting of Employer-Sponsored Health Coverage

Code C reports the taxable cost of group-term life insurance above $50,000 of coverage. This amount is already included in Boxes 1, 3, and 5; Box 12 just breaks it out for transparency.3IRS.gov. Group Term Life Insurance

Why Box 1 Sometimes Looks Higher Than People Expect

Roth contributions cause the most confusion. If you contribute to a Roth 401(k) or Roth 403(b), your Box 1 wages will be higher than they would with a traditional pre-tax deferral of the same amount. Roth contributions are taxed now in exchange for tax-free withdrawals later, so they stay in Box 1. They still appear in Box 12 under Code AA or Code BB, but those codes are informational because the money has already been taxed.8Internal Revenue Service. Common Errors on Form W-2 Codes for Retirement Plans

Someone contributing $10,000 to a traditional 401(k) and an identical coworker contributing $10,000 to a Roth 401(k) will have Box 1 figures that differ by exactly $10,000, even though their gross pay, Box 3, and Box 5 all match. If your Box 1 seems too high, check whether your plan is set to Roth.

Checking Box 1 Against Your Last Paystub

When your W-2 arrives, it is worth reconciling Box 1 against your final paystub of the year. Your year-to-date gross earnings should be higher than Box 1, and the difference should roughly equal the sum of your pre-tax deductions: retirement deferrals, health insurance premiums, FSA elections, and HSA contributions made through payroll. If adding your Box 12 Code D (or E, or S) amount back to Box 1 does not close the gap, look at your cafeteria plan deductions. Those are excluded from Box 1 but do not always appear individually in Box 12.

Your take-home pay will be smaller than any of the wage boxes because it also reflects income tax withholding, FICA, and any after-tax deductions like Roth contributions or garnishments. Net pay does not appear anywhere on the W-2.

Two Situations That Change How You Use Box 1

Statutory Employees

If the “Statutory employee” box in Box 13 is checked, Box 1 does not go on line 1 of your Form 1040 the usual way. Statutory employees, which include certain delivery drivers, full-time life insurance salespeople, and qualifying home workers, do not have federal income tax withheld. They report their Box 1 income on Schedule C and deduct business expenses against it, similar to self-employed filers.13Internal Revenue Service. Statutory Employees FICA is withheld normally, so Boxes 3 and 5 work the same as on any other W-2.

Multiple Jobs and Excess Social Security Tax

Each employer withholds Social Security tax up to the $184,500 wage base independently. If you worked two or more jobs and your combined wages exceeded the cap, you may have overpaid, because neither employer knew about the other. You can claim the excess as a credit on your Form 1040, and on a joint return each spouse calculates the overpayment separately.14Internal Revenue Service. Topic No. 608, Excess Social Security and RRTA Tax Withheld If you had more than one W-2 and your combined Box 3 figures top $184,500, run the numbers before you file.