What this line means
The portion of your wages subject to Social Security tax. Box 3 is usually higher than Box 1 because most pre-tax deductions that reduce Box 1 (like 401(k) contributions and health insurance premiums) do not reduce Social Security wages. Box 3 is capped at the Social Security wage base — $176,100 for 2025. If you earned more than that from one employer, Box 3 stops at the cap.
Does this apply to you?
- You earned wages from a W-2 employer during the year
- You contributed to a 401(k) or 403(b) and noticed Box 3 is higher than Box 1
- You earned over the Social Security wage base and see Box 3 capped at $176,100
- You had multiple employers and the combined Box 3 amounts exceed the wage base
Easy to overlook
Box 3 and Box 1 are supposed to be different Filers see two different dollar amounts and assume something is wrong. Box 1 excludes pre-tax 401(k) contributions, but Box 3 includes them because 401(k) deferrals are exempt from income tax but not from Social Security tax. A person earning $90,000 with a $10,000 401(k) contribution sees $80,000 in Box 1 but $90,000 in Box 3. 1 IRS Publication 15 (Circular E) — pre-tax deduction treatment
Excess Social Security tax from multiple employers is refundable If you worked two or more jobs and the combined Box 3 amounts exceed $176,100, too much Social Security tax was withheld. Each employer withheld independently up to the cap. You claim the excess as a credit on your 1040. This is real money back — at 6.2%, the overpayment from even a small overlap can be several hundred dollars. 2 SSA wage base limit — 2025 cap at $176,100
Watch out for this
Not claiming a refund for excess Social Security tax when you had multiple employers. If Employer A withheld Social Security tax on $100,000 and Employer B withheld on $90,000, the combined $190,000 exceeds the $176,100 cap. You overpaid 6.2% on $13,900 — that is $861.80 you are owed. This credit is claimed on Form 1040, Schedule 3.
Footnotes
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IRS Publication 15 (Circular E), Employer’s Tax Guide, Wages and Other Compensation. https://www.irs.gov/pub/irs-pdf/p15.pdf ↩
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Social Security Administration, 2025 Social Security Wage Base. https://www.ssa.gov/oact/cola/cbb.html ↩