What is OASDI on my paystub? (Hint: it's Social Security)
OASDI explained — what it is, how much you pay, when it stops, and why it disappears halfway through the year for some people.
OASDI is one of the most confusing line items on a paystub — partly because it doesn't look like what it actually is. The three-letter answer: it's Social Security tax. But the longer answer explains a few quirks that confuse people every year.
What OASDI stands for
OASDI = Old Age, Survivors, and Disability Insurance. That's the technical name of the Social Security program. Some payroll systems use 'SS' or 'FICA-SS' instead. They all mean the same thing.
How much you pay
6.2% of every dollar you earn, up to an annual wage base. The wage base goes up almost every year:
- 2024: 6.2% up to $168,600
- 2025: 6.2% up to $176,100
- Above the wage base, OASDI stops withholding for the rest of the calendar year
Your employer also pays 6.2%, so the total going to the Social Security trust fund is 12.4% of your wages. That's why hiring you costs your employer more than your salary.
Why your OASDI deduction sometimes disappears
If you're a high earner, your OASDI line vanishes from your paystub once your year-to-date wages cross the wage base. For a 2025 earner making $200,000 at a constant pay rate, OASDI stops around mid-October. Your take-home jumps by 6.2% the next pay period.
Got two jobs?
If you had two W-2 jobs and each one withheld OASDI up to the wage base, you may have overpaid. The IRS lets you reclaim the excess on Form 1040, line 11. Your employers can't coordinate this — you have to claim it yourself.
Is OASDI deductible?
No. Unlike federal income tax, OASDI is not a prepayment toward your annual tax bill. You don't reconcile it on your return, and you can't write it off. You're paying it now and getting Social Security benefits in retirement in exchange.
Where it lands on your W-2
- Box 4 — total OASDI withheld for the year
- Box 3 — wages the OASDI tax was calculated on (often higher than Box 1)
If you're curious how OASDI plays into your overall paystub — gross vs. net, pre-tax deductions, the W-2 wage difference — upload your PDF on the homepage and the AI breakdown will show it all in context.
See it in your own paystub
Upload your PDF and the AI will show how every line plays into the bigger picture.
Affiliate link — we may earn a commission at no cost to you.