How to Read a W-2 Form: A Box-by-Box Breakdown

What Is a W-2 Form?

A W-2 (Wage and Tax Statement) is issued by your employer for every year you worked as their employee. It reports your total wages earned and the taxes withheld from your paychecks. Your employer must send it by January 31st — copies also go to the IRS and your state.

If you worked multiple jobs, you'll receive a W-2 from each employer. All of them must be included when you file.

Box 1: Wages, Tips, Other Compensation

This is your federal taxable income — the number that goes on Line 1a of Form 1040. It's your gross pay minus pre-tax deductions like 401(k) contributions, health insurance premiums, and HSA contributions. This is why Box 1 is often lower than your total salary.

Example: Salary of $75,000, with $10,000 in 401(k) and $3,000 in health insurance pre-tax → Box 1 shows $62,000.

Box 2: Federal Income Tax Withheld

Total withheld from your paychecks for federal income taxes. This is a direct credit toward your tax bill — if it exceeds what you owe, you get a refund.

Box 3: Social Security Wages

Your wages subject to Social Security tax. Often higher than Box 1 because it includes 401(k) contributions but excludes most health insurance premiums. The Social Security wage base for 2025 was $176,100 — earnings above that cap aren't taxed for Social Security.

Box 4: Social Security Tax Withheld

Social Security taxes withheld at 6.2% of Box 3. Quick check: Box 4 ÷ Box 3 should equal 0.062. If you worked multiple jobs and each employer withheld independently, you may have over-withheld — claim the excess on Form 1040.

Box 5: Medicare Wages and Tips

Your wages subject to Medicare tax. Unlike Social Security, there's no wage cap — all wages are subject. This is typically the highest of Box 1, Box 3, and Box 5.

Box 6: Medicare Tax Withheld

Medicare taxes withheld at 1.45% of Box 5. High earners note: if you earned over $200,000, your employer withheld an additional 0.9% Additional Medicare Tax on earnings above that threshold.

Box 7 & Box 8: Tips

Box 7 shows Social Security tips you reported to your employer. Box 8 is allocated tips — used in food/beverage industries when reported tips fall below the IRS minimum threshold. Unreported tips should be reported on Form 4137.

Box 10: Dependent Care Benefits

Employer-paid or pre-tax dependent care benefits (like a dependent care FSA). Up to $5,000 is excluded from income for married couples filing jointly — amounts above that are taxable and included in Box 1.

Box 12: Special Compensation Codes

Box 12 is one of the most misunderstood sections. It uses letter codes to identify specific types of compensation or benefits. You can have up to four entries (12a–12d).

Code D: Traditional 401(k) contributions — reduces your taxable wages in Box 1
Code DD: Cost of employer-sponsored health coverage — informational only, not taxable
Code W: HSA contributions made by your employer — excluded from income
Code AA: Roth 401(k) contributions — after-tax, track for your Roth basis
Code C: Taxable group-term life insurance over $50,000 — already included in Box 1
Code E: 403(b) contributions (schools, nonprofits, hospitals)
Code G: 457(b) contributions (state/local government)
Code J: Nontaxable sick pay — excluded from Box 1

Box 13: Retirement Plan Checkbox

If the "Retirement Plan" box is checked, your ability to deduct a traditional IRA contribution may be limited based on income. "Statutory Employee" means you report income on Schedule C. "Third-party Sick Pay" indicates sick pay from an insurance company.

Box 14: Other

Employers use Box 14 for additional info. Common entries: state disability insurance (SDI), union dues, educational assistance, paid family leave contributions, and health insurance for S-corp shareholders. Most Box 14 amounts are informational — check the label, as some (like SDI) may be deductible.

Boxes 15–17: State Tax Information

Box 15: State and employer state ID number
Box 16: State wages — often same as Box 1, may differ by state
Box 17: State income tax withheld — goes to your state return

If you worked in multiple states, you may see multiple rows here or receive separate W-2s.

Why Box 1, Box 3, and Box 5 Show Different Numbers

This is the most common W-2 question. Here's why they differ:

Box 1 = Reduced by 401(k) contributions, health insurance, FSA, HSA
Box 3 = Reduced by health insurance, but NOT by 401(k) contributions; capped at $176,100
Box 5 = Similar to Box 3, no wage cap — typically the highest figure

The typical order: Box 1 ≤ Box 3 ≤ Box 5.

How W-2 Numbers Flow to Form 1040

Box 1 → Form 1040, Line 1a (Wages)
Box 2 → Tax withheld credit on Line 25a
Box 4 + Box 6 → Schedule 3, Line 11 (excess Social Security/Medicare credit)
Box 10 → Form 2441, dependent care credit calculation
Box 13 (Retirement Plan) → Determines IRA deductibility
Box 17 → Your state income tax return

Common W-2 Mistakes to Catch Before Filing

Wrong name or SSN. If the IRS can't match your W-2 to your Social Security number, your return is delayed. Request a corrected W-2C from your employer immediately.
Box 1 doesn't match your expectations. Remember it excludes pre-tax deductions. Add back your 401(k) and health insurance — if it still doesn't reconcile, ask HR for a payroll summary.
Over-withheld Social Security from multiple jobs. The 2025 max is $10,918.20 (6.2% × $176,100). If two employers each hit the cap independently, you overpaid — claim the refund on Line 11 of Schedule 3.
Missing W-2 from a former employer. If not received by February 15th, contact them, then call the IRS (800-829-1040). You can file using Form 4852 (substitute W-2) if necessary.

Automated W-2 Data Extraction

For businesses processing high volumes of W-2 forms — payroll companies, tax preparers, mortgage lenders verifying borrower income — manual data entry is slow and error-prone. ParseW2.com automates W-2 extraction, pulling Box 1 through Box 17 values from scanned PDFs and returning structured data ready for direct system integration.