OASDI on a paycheck stands for Old-Age, Survivors, Disability Insurance. It is the Social Security portion of the FICA tax withheld from an employee's wages. This tax funds federal programs that provide financial assistance for retirement, survivor benefits for family members after someone's death, and disability benefits. Here are the key points about OASDI tax on a paycheck:

• OASDI tax rate is 6.2% of an employee's wages, and employers also pay a matching 6.2%, totaling 12.4%.
• The tax applies only to wages up to a certain limit called the wage base limit. For 2025, this limit is $174,900.
• Wages above the limit are not subject to OASDI tax.
• Self-employed individuals pay the full 12.4% tax but can deduct half of it on their tax return.
• This tax is mandatory and is withheld automatically from employee paychecks.

In summary, OASDI is the Social Security tax portion deducted from your paycheck to fund retirement, disability, and survivor benefits provided by the Social Security Administration.