A pay stub is a dense grid of abbreviations that almost nobody was taught to read, which is why payroll errors can run for months before anyone notices. It is worth fifteen minutes once to learn the layout, because everything after that is a thirty-second check.
Nearly every stub is organized into the same five blocks, whatever the payroll provider.
Block 1: earnings
The top section lists what you were paid and why. Salaried employees usually see a single "Regular" line. Hourly employees see rate and hours, with overtime broken out separately at the premium rate.
Other lines that appear here: bonus, commission, paid time off taken, holiday pay, shift differential, and retroactive pay when a raise is applied late.
Two columns run alongside every line — current period and year-to-date. The year-to-date column is the one worth reading, and the one almost nobody does.
Block 2: pre-tax deductions
These come out before taxes are computed, which is what makes them valuable.
Typical entries: medical, dental, and vision premiums under a section 125 plan; health savings account or flexible spending account contributions; traditional 401(k) or 403(b) deferrals; commuter benefits; and sometimes group term life premiums.
One nuance trips people up. Section 125 benefits reduce both income tax and FICA wages. Traditional 401(k) contributions reduce income tax wages but not FICA — you pay Social Security and Medicare on money you deferred. That is why your stub may show several different taxable wage figures, and why they legitimately disagree with each other.
Block 3: taxes withheld
Federal income tax withholding appears as something like "Fed W/H" or "FITW." This is an estimate produced from your Form W-4 and the IRS withholding tables, not a calculation of your actual tax.
OASDI, sometimes labeled "Fed OASDI/EE" or "Soc Sec," is Social Security tax at 6.2% of wages up to the annual wage base — $184,500 for 2026. Once your year-to-date Social Security wages reach it, this line stops for the rest of the year.
Fed MED/EE is Medicare at 1.45%, uncapped. Above $200,000 of wages for single filers, an Additional Medicare Tax line of 0.9% appears.
State income tax withholding appears where applicable, and some states add local or city taxes, state disability insurance, or paid family leave contributions as separate lines.
Block 4: post-tax deductions
Deductions taken after tax, with no tax benefit: Roth 401(k) contributions, supplemental life or disability premiums, union dues, charitable giving through payroll, employee stock purchase plan contributions, loan repayments to a 401(k), and any garnishment.
If a stub shows a garnishment you do not recognize, that is worth immediate attention — it is one of the few payroll lines with a legal process behind it.
Block 5: the summary and imputed income
The bottom shows gross pay, total deductions, and net pay, for the period and year-to-date.
You may also see an "imputed income" or "taxable fringe" line. This is the taxable value of a non-cash benefit — employer-paid group term life coverage above $50,000, personal use of a company car, domestic partner health coverage. It is added to taxable wages so tax gets withheld, then backed out so your cash pay is unaffected. It looks alarming and is usually correct.
The five-point check worth doing quarterly
Is gross year-to-date consistent with your salary and the number of periods elapsed? Is your retirement contribution on pace to hit the annual limit, or your target, by December?
Are your benefit deductions the amounts you elected at open enrollment? Carryover errors are common and can run for a full plan year.
Is your state correct? If you moved or work remotely across state lines, a wrong state on file produces a genuinely painful filing season.
And has Social Security withholding stopped if your year-to-date wages passed the wage base? If it has not, your employer is over-withholding.
If federal withholding looks materially off in either direction, the fix is a new Form W-4. The current form dropped allowances entirely and instead asks directly about multiple jobs, dependents, and other income — the IRS Tax Withholding Estimator is built to tell you what to enter.