Accountants do not read pay stubs top to bottom. They run a 5-minute audit, and the whole thing fits on an index card: verify gross, sort the deductions into pre-tax and post-tax, check the FICA math, then read the YTD column for errors. That is how to read your pay stub like an accountant, and it catches more mistakes than you would expect from a document your employer generates by computer.
Let me make it concrete with a real example. Say you earn $75,000 a year, paid biweekly, which is 26 paychecks. Your gross per period is $2,884.62. You contribute 6% to your 401(k), which is $173.08, and your health insurance premium is $150 per paycheck. Federal withholding comes to about $230, state to about $100. Run the audit.
Gross is the biggest number on the stub and the easiest to check. Hourly: rate times hours, including overtime at the right multiplier. Salaried: annual salary divided by pay periods. If your $75,000 salary is paid biweekly, gross should be exactly $2,884.62, not $2,884.00, not $2,890. Payroll systems do not round your salary. If the gross is wrong, everything downstream is wrong, so this is always the first line you check.
This is the part most people skip, and it is where the money hides. Pre-tax deductions come out before income tax is calculated, which lowers your taxable income. Post-tax deductions come out after, which does not. On our example stub:
Social Security is 6.2% of your FICA wages, and Medicare is 1.45%. On our stub, FICA wages are gross minus the health premium: $2,884.62 minus $150 is $2,734.62. Social Security should be $169.55. Medicare should be $39.65. If your stub shows something meaningfully different, flag it. The usual culprit is the 401(k) being wrongly excluded from FICA wages, or a bonus being run through a separate check with different withholding.
Then the YTD check that catches the most expensive error: Social Security stops at the wage cap, $184,500 for 2026. Once your YTD Social Security wages cross that line, the 6.2% deduction should be zero for the rest of the year. If it keeps coming out, that is real money, about $440 a month on a high salary, and payroll owes you a correction.
The year-to-date column is the whole audit trail. Multiply your per-period 401(k) by the number of paychecks so far and compare it to YTD contributions: for 2026 the limit is $24,500, and over-contributing through two jobs in one year is a genuinely common mistake. Compare YTD federal withholding to what you expect to owe; October is the last comfortable month to adjust your W-4. And in December, hold your final stub against the W-2 when it arrives in January. They should match closely. A large gap means something was reclassified after the last payroll run, and you want to know before you file.
Gross pay is everything you earned in the pay period before anything is taken out. Net pay is what is left after all deductions: taxes, benefit premiums, and retirement contributions. The check is simple: gross minus total deductions should equal net, every period.
Year to date: the running total from January 1 through the current pay period. Every line on the stub usually has a YTD column next to the current-period column. YTD totals are how you catch errors, like Social Security tax that keeps coming out after you passed the wage cap.
No. Pre-tax 401(k) contributions reduce your federal income tax, but they are still subject to Social Security and Medicare taxes. Health insurance premiums paid through a Section 125 plan do reduce FICA wages, which is one reason they are such a good deal.
Withholding that was never updated after a W-4 change, Social Security tax that does not stop at the $184,500 wage cap, duplicate benefit deductions after open enrollment, and PTO balances that do not match what you actually took. The YTD column is where most of these surface.
Closely, yes. Your final stub's YTD gross, federal wages, and withholding should line up with the W-2 your employer issues in January. A large discrepancy is worth investigating with payroll before you file.
One practical money guide a week. Real numbers, no fluff.