Quick Answer
Form W-2 has 20+ boxes showing your wages, taxes withheld, and benefits. Box 1 shows taxable wages (often less than Box 5 due to pre-tax deductions), Box 2 shows federal tax withheld, and Box 12 contains benefit codes. The average W-2 shows $15,000-$20,000 less in Box 1 than gross salary due to pre-tax deductions.
Best Answer
Diana Flores, EA
Anyone who receives a W-2 and needs to understand the basics for tax filing
What are the key boxes on Form W-2?
Form W-2 contains over 20 boxes, but most taxpayers only need to focus on 8-10 key boxes for accurate tax filing. According to IRS Publication 15-A, employers must report specific wage and tax information in designated boxes to ensure proper tax calculation.
Here's what each major box represents:
Box 1 - Wages, tips, other compensation: This is your taxable income after pre-tax deductions. If you earned $75,000 but contributed $4,500 to your 401(k) and paid $2,400 for health insurance, Box 1 shows $68,100.
Box 2 - Federal income tax withheld: The total federal tax your employer withheld from your paychecks. This gets credited against your tax liability when you file.
Box 3 - Social Security wages: Usually matches Box 1, but capped at the Social Security wage base ($176,100 for 2026). Pre-tax deductions reduce this amount.
Box 4 - Social Security tax withheld: Should be 6.2% of Box 3, up to $10,918 maximum for 2026.
Box 5 - Medicare wages and tips: Similar to Box 3 but with no wage cap. All earned income is subject to Medicare tax.
Box 6 - Medicare tax withheld: Should be 1.45% of Box 5, plus 0.9% additional Medicare tax on wages over $200,000.
Example: Reading a typical W-2
Let's examine a W-2 for someone earning $80,000 annually with common pre-tax deductions:
State and local tax boxes
Boxes 15-20 handle state and local tax information:
Other important boxes
Box 7 - Social Security tips: Only applies if you received tip income and reported it to your employer.
Box 8 - Allocated tips: Rare - only for large food/beverage establishments that must allocate tips to employees.
Box 9 - [Blank]: This box is intentionally left blank.
Box 10 - Dependent care benefits: Employer-provided dependent care assistance, up to $5,000 tax-free.
Box 11 - Nonqualified plans: Distributions from nonqualified deferred compensation plans.
Box 13 - Checkboxes: Three boxes for:
Box 14 - Other: Miscellaneous items like union dues, uniform costs, or other deductions.
What to verify on your W-2
Check these calculations:
1. Box 4 should equal 6.2% of Box 3 (unless you hit the Social Security wage cap)
2. Box 6 should equal 1.45% of Box 5 (plus additional 0.9% if Box 5 exceeds $200,000)
3. Box 1 should equal your gross pay minus pre-tax deductions
4. State withholding (Box 17) should align with your state tax rate and filing status
Red flags to watch for:
What you should do
1. Compare your W-2 to your final paystub - they should match exactly
2. Verify all pre-tax deductions are properly reflected in the difference between gross pay and Box 1
3. Check that retirement plan eligibility is marked correctly in Box 13
4. Use our form explainer tool to get a detailed breakdown of any confusing codes or amounts
5. Contact your payroll department immediately if you find errors - corrections get harder after January 31st
Key takeaway: Your W-2's Box 1 (taxable wages) is typically $10,000-$25,000 less than your gross salary due to pre-tax deductions like 401(k), health insurance, and FSA contributions. Always verify the math matches your final paystub before filing your taxes.
Key Takeaway: Your W-2's Box 1 shows taxable wages after pre-tax deductions, typically $10,000-$25,000 less than gross salary, and should match your final paystub exactly.
Key W-2 boxes and what they represent for tax filing
| Box | What It Shows | Goes To | Why It Matters |
|---|---|---|---|
| 1 | Taxable wages after pre-tax deductions | Form 1040, Line 1a | Determines your taxable income |
| 2 | Federal income tax withheld | Form 1040, Line 25a | Credits against tax owed |
| 3 | Social Security wages (capped at $176,100) | Automatic calculation | Ensures correct FICA |
| 5 | Medicare wages (no cap) | Automatic calculation | Determines Medicare tax |
| 12 | Pre-tax benefits and deductions | Various forms | Affects multiple tax benefits |
| 16 | State wages | State tax return | State income calculation |
| 17 | State tax withheld | State tax return | State tax credits |
More Perspectives
Diana Flores, EA
W-2 employees with straightforward tax situations who take the standard deduction
The 5 boxes that matter most for simple filers
If you're a W-2 employee taking the standard deduction, you only need to focus on five key boxes when reviewing your W-2:
Box 1 - Your taxable income: This number goes directly on Line 1a of Form 1040. It's your salary minus any pre-tax deductions like health insurance or 401(k) contributions.
Box 2 - Federal tax already paid: This is your "down payment" on your tax bill. If this number is close to your actual tax owed, you'll get a small refund or owe a small amount.
Boxes 16 and 17 - State wages and state tax withheld: These numbers transfer to your state tax return. Most states follow federal rules, so Box 16 usually matches Box 1.
Box 12 - Pre-tax benefits: Look for codes D (401k), C (group life insurance), or DD (employer health coverage cost). These codes can affect other tax benefits.
Quick accuracy check
For simple filers, here's the fastest way to verify your W-2 is correct:
1. Add up all your paystubs' gross pay - this should be more than Box 1
2. Add up all federal tax withheld from paystubs - this should match Box 2 exactly
3. Check that Box 13 has "Retirement plan" marked if you were eligible for a 401(k), even if you didn't contribute
Most errors simple filers encounter involve incorrect federal withholding (Box 2) or missing retirement plan eligibility marking (Box 13). The retirement plan checkbox affects your IRA deduction eligibility, potentially costing you up to $7,000 in deductions if marked incorrectly.
When to use the form explainer
Use our form explainer tool if:
Key takeaway: Simple filers need to verify five boxes: taxable wages (1), federal withholding (2), state wages/withholding (16/17), and retirement plan eligibility (13). These five numbers determine 95% of your tax return accuracy.
Key Takeaway: Simple filers only need to verify five key boxes on their W-2, with Box 1 (taxable wages) and Box 2 (federal withholding) being the most critical for accurate tax filing.
Sources
- IRS Publication 15-A — Employer's Supplemental Tax Guide
- IRS Instructions for Form W-2 — Official instructions for preparing Form W-2
Reviewed by Diana Flores, EA on February 28, 2026
This content is for educational purposes only and is not a substitute for professional tax advice. Consult a qualified tax professional for advice specific to your situation.