What is OASDI on my paycheck?

OASDI is the Social Security tax. The letters stand for Old-Age, Survivors and Disability Insurance, the official name of the Social Security program. Your employer withholds 6.2% of your wages for it, up to $184,500 of wages in 2026, and pays a matching 6.2% of its own.

Some payroll systems print OASDI, others SS or Social Security. They all mean the same line. Next to it you will usually see Medicare, sometimes printed as MED or HI, at 1.45%. Together the two make up FICA.

On a $2,307.69 paycheck, OASDI is $143.08. Once your pay for the year passes the wage base, the line drops to zero until January, so high earners see bigger checks late in the year. Health premiums taken before tax lower it, while a 401(k) does not. See the OASDI entry.