How to Read Your Pay Stub
OASDI, FED MED/EE, YTD, imputed income. A plain-language guide to every abbreviation on a US pay stub and what it is taking from you.
Pay stubs are written for payroll software, not for people. Here is what each part means.
The three blocks
Almost every US stub splits into earnings, deductions, and net pay, with a year-to-date column running alongside.
Earnings is what you were paid before anything came out. If you are hourly you will see rate and hours; if you are salaried you will see a flat period amount. Overtime, bonuses and commission appear as separate lines because they are often taxed differently.
Deductions is everything removed, usually split into pre-tax and post-tax sections. The order matters: pre-tax items come out before tax is calculated, so they reduce what you owe.
Net pay is what hits your account.
Decoding the abbreviations
| Label | Meaning |
|---|---|
| FED, FIT, FWT | Federal income tax withheld |
| OASDI, SS, FICA-SS | Social Security, 6.2% |
| MED, FED MED/EE | Medicare, 1.45% |
| ADDL MED | Additional Medicare, 0.9% above $200,000 |
| SIT, ST TAX | State income tax |
| SUI, SDI | State unemployment or disability insurance |
| YTD | Year to date |
| IMP INC | Imputed income — see below |
| S125 | Section 125 cafeteria plan (pre-tax benefits) |
Imputed income catches people out
If you see a line adding to your taxable wages that you never received as cash, that is imputed income — the taxable value of a benefit your employer provided.
The most common source is employer-paid group life insurance above $50,000 of coverage. The IRS treats the value of the excess as taxable compensation, so it increases your taxable wages and your tax without ever increasing your pay. Domestic partner health coverage and personal use of a company car work the same way.
It looks like an error. It usually is not.
Pre-tax versus post-tax
This is the single most useful distinction on the page.
Pre-tax deductions come out before income tax is calculated: traditional 401(k), Section 125 health premiums, HSA and FSA contributions, commuter benefits. Health premiums also reduce your Social Security and Medicare wages, which almost nothing else does.
Post-tax deductions come out of money that has already been taxed: Roth 401(k), union dues, garnishments, most disability premiums.
Two deductions of the same dollar amount can have very different effects on your take-home pay depending on which side of the line they fall.
Checking the YTD column
Once a year, do this: multiply the current period's gross by the number of pay periods elapsed and compare it to the YTD gross. If they do not roughly match, something changed — a raise, a missed period, a correction — and it is worth asking about.
Also check that your Social Security YTD stops growing once you pass the wage base. In 2026 that is $184,500. If deductions continue past it, you are being over-withheld and should raise it with payroll immediately.
Common questions
What does OASDI mean on my pay stub?
OASDI stands for Old-Age, Survivors, and Disability Insurance — the formal name for Social Security. It is withheld at 6.2% of wages up to the annual wage base, which is $184,500 in 2026.
What is imputed income on a pay stub?
Imputed income is the taxable value of a non-cash benefit, such as employer-paid life insurance above $50,000 of coverage or domestic partner health coverage. It increases your taxable wages without increasing your actual pay.
What is the difference between pre-tax and post-tax deductions?
Pre-tax deductions such as a traditional 401(k) or Section 125 health premiums come out before income tax is calculated, reducing your taxable income. Post-tax deductions such as Roth 401(k) contributions or union dues come out of already-taxed pay.