Old Age, Survivors & Disability Insurance
This is your Social Security tax — 6.2% of your wages up to $168,600/year. It funds retirement, disability, and survivor benefits.
Who pays it
Every W-2 employee pays OASDI. Self-employed people pay the equivalent through SECA (the self-employment tax), which is double — they cover both the employee and employer side.
How much
6.2% of every dollar you earn, up to the annual wage base ($168,600 in 2024, $176,100 in 2025). Once you cross the cap, the deduction stops for the rest of the year.
Where it appears on your W-2
Box 4 of your W-2 shows your total OASDI/Social Security tax withheld for the year. Box 3 shows the wages it was calculated on.
Tax impact
OASDI is not deductible — you can't write it off on your tax return. It is, however, post-tax in the sense that it doesn't reduce your federal taxable income. Your 401(k) and HSA reduce Box 1 wages; OASDI does not.
Common questions about OASDI
Why did my OASDI deduction stop mid-year?
You hit the annual wage cap. Once your year-to-date wages cross $168,600 (2024), OASDI withholding stops. It restarts on January 1.
Can I get my OASDI back if I overpaid?
Only if you had two jobs and combined OASDI withholding exceeded the annual maximum. You claim the excess back on Form 1040, line 11.
Is OASDI the same as Social Security?
Yes — OASDI stands for Old Age, Survivors, and Disability Insurance, which is the technical name for the Social Security program.
Filing your taxes?
If understanding OASDI is part of getting your return right, these tools handle the math for you.
Affiliate links — we may earn a commission at no cost to you.
See OASDI in your own paystub
Upload your PDF and our AI will show you exactly how OASDI interacts with the rest of your deductions.
Upload paystub →