Paystub Abbreviations Decoded: FICA, OASDI, LST, EIT, SDI and the Rest

Nobody teaches you to read a paystub, and payroll systems seem to prefer it that way — every line is a cryptic four-letter code next to a number going the wrong direction. But each abbreviation is just a tax, an insurance premium, or a savings deduction with a formal name. Once you can read them, a paystub stops being a mystery and becomes a receipt you can actually audit.

FICA / OASDI / Medicare — the federal payroll taxes

• FICA is the umbrella: the Federal Insurance Contributions Act combines Social Security and Medicare into one payroll tax.
• OASDI is Social Security by its formal name — Old-Age, Survivors, and Disability Insurance. 6.2% of wages up to the $184,500 wage base in 2026.
• MED or Medicare is the 1.45% hospital-insurance tax on every dollar, plus 0.9% more above $200,000 for single filers.
• Some stubs show FICA as one line; others split OASDI and Medicare. Same money, different label.

FED / STATE / LOCAL — income tax withholding

FED W/H (or FIT, federal income tax) is the income tax withheld from each check based on your W-4. SIT or STATE W/H is your state income tax, if your state has one. These are estimates against your annual return — not a separate bill — which is why fixing your W-4 changes them.

LST / EIT / SDI / SUI — the state-specific alphabet

• LST (Local Services Tax) and EIT (Earned Income Tax) appear on Pennsylvania paystubs — local taxes most calculators ignore.
• SDI is State Disability Insurance in California, New Jersey, New York, Rhode Island and Hawaii — a small employee-paid insurance premium, not income tax.
• SUI (State Unemployment Insurance) is usually employer-paid, but a few states withhold a small employee share.
• Ohio stubs often show a city code — that is your municipal income tax. Indiana stubs show a county code for the county tax.

401(k) / 125 / GTL — the deductions that are actually yours

• 401(k), 403(b) or TSP is your retirement contribution — pre-tax for income tax, but still hit by FICA.
• SEC 125 or CAF125 is your Section 125 cafeteria plan: medical, dental and vision premiums paid pre-tax, escaping both income tax and FICA.
• GTL (Group Term Life) is the taxable value of employer life insurance above $50,000 of coverage — it adds to taxable wages even though no cash moved.
• YTD is not a deduction at all — it is the year-to-date running total, the column to watch for the Social Security wage base crossover.

A two-minute stub audit

Add up the codes once: OASDI should be 6.2% of taxable wages, Medicare 1.45%, and the pre-tax lines should match what you elected at enrollment. Then run your salary through the calculator — federal, state and FICA should land close to its estimate. Any code you still cannot identify after this list is worth one email to payroll; it is your money on every line.

Sources

• IRS Publication 15 (Circular E) — federal payroll tax definitions.
• Social Security Administration — OASDI rates and the 2026 wage base.
• State revenue and workforce agencies — SDI, SUI, LST and EIT programs.