I've Read 4,000 Pay Stubs. Here's What Yours Is Actually Telling You.
About four years into my career I picked up a tax season side rotation reviewing payroll for a regional CPA firm. The partner handed me a stack of W-2s and what felt like a thousand year-end stubs and said “find the errors.” I thought he was joking. He wasn’t. Roughly one stub in eight had something wrong on it — the wrong state code after a move, a healthcare premium still flowing post-tax after open enrollment, an HSA contribution sitting in the FSA bucket, a 401(k) deferral that didn’t restart after a leave. Once you know what to look for, the stub will tell you. Most people just don’t know what to look for.
So this is what I wish every employee at the firm read before their first January W-2. It walks the typical 2026 US pay stub from top to bottom, points out the exact spots where payroll engines drift, and explains why three different “wage” numbers show up on the same piece of paper without contradicting each other. I’ll use the ADP / Paychex / Workday-style layout because that covers something like 80% of the private workforce. The field names will look different on your stub. The categories won’t.
The header you skim and shouldn’t
The top block names the legal employer (often a corporate parent you’ve never heard of), your worker class, the pay period dates, and a pay date. People skip it. Bad habit. The dates are where a partial check after a promotion or a transfer overlaps or leaves a one-day gap, and that one day becomes a phone call to HR three weeks later when the YTD numbers don’t reconcile. Check that the period actually matches the days you worked. Check that filing status reads what you put on your W-4 — not what you put on it in 2017, but what you have on it now. Step 2(c) on the 2020-and-later W-4 (the “Multiple jobs” checkbox) is the single most-missed field. If you and a spouse both work and that box is empty on both W-4s, you are almost certainly under-withheld. Quietly. All year.
Earnings — gross before anything else
Everything paid before tax and before any deduction shows up in this section. Salaried folks usually see one line called Regular, Salary, or Base, and that’s the whole story. Hourly and shift workers get a fuller picture: regular hours, overtime, double time, holiday, vacation, sick, bereavement, jury, shift differential, bonus, commission, retro pay, plus non-taxable reimbursements like mileage at $0.705 per mile in 2026.
A few of these are worth pulling apart. Overtime under the federal Fair Labor Standards Act is 1.5x your regular rate for hours past 40 in a single workweek. Californians get extra protections — daily overtime triggers after 8 hours, double time after 12, and double time on the 7th consecutive day of work. Colorado and Alaska have daily overtime rules too. If you don’t live in one of those three states and your employer is paying you daily overtime, the federal rule doesn’t require it — you’re getting a contractual benefit, not a legal one. Supplemental wages like bonuses and commissions get withheld using one of two methods the IRS approves: a flat 22% under $1M, or the aggregate method that mixes the bonus with your regular wages and runs the combined amount through the withholding tables. That’s why a December bonus check often feels like the IRS took half of it. They probably didn’t. They just withheld at a percentage that doesn’t match your actual marginal rate. The difference comes back at filing. (Or, painfully, you owe more, if you’re in the 32%+ bracket.) Our bonus tax calculator models both methods side by side if you want to see which one your employer is using.
The bottom of the earnings block is your gross. Sometimes labeled Gross Earnings, Current Period Earnings, Total Earnings, or just Gross. Every subsequent calculation on the stub flows from this number. If it’s wrong, everything else is wrong, and the entire stub is suspect. Confirm against the rate and schedule on your offer letter at least once a quarter.
Pre-tax deductions: the most important block on the page
This is where most of the take-home-pay leverage lives, and it’s also where I see the most enrollment errors. Pre-tax deductions are authorized by specific sections of the Internal Revenue Code — Section 125 covers the cafeteria plan that wraps your health, dental, vision, FSA, and dependent-care FSA; Section 401 covers the traditional 401(k), 403(b), and 457(b); Section 132 covers commuter and parking; Section 79 covers group-term life under $50,000 of coverage; Section 223 covers the HSA. Each section specifies which taxes the deduction reduces, and the wrinkle that catches people is that a traditional 401(k) reduces your federal income tax wages but does not reduce your FICA wages. The 7.65% on Social Security and Medicare comes out the same whether you defer or not. Health premiums and HSA through payroll, on the other hand, reduce all three tax bases. That’s why open enrollment math should start with HSA before extra 401(k).
Specifically, in 2026: 401(k) deferral is capped at $23,500 ($31,000 if you’re 50 or older, $34,750 if you’re between 60 and 63 under the SECURE 2.0 super catch-up). HSA limits are $4,400 self-only and $8,750 family, with another $1,000 if you’re 55+. Healthcare FSA is $3,300 with a $660 federal carryover maximum if your plan allows it. Dependent-care FSA is $5,000 per household ($2,500 if married filing separately). Commuter transit and parking are each $325 per month. Group-term life over $50,000 of coverage creates imputed income that’s taxed but not deducted — you’ll see it as a small add-on to taxable wages with no corresponding cash deduction.
The three wage numbers, and why your W-2 looks “wrong”
This is the part that confuses first-time filers every January. Your stub has three different wage figures and your W-2 in January will too. They will all be different from each other and that is correct. Don’t call HR yet.
Federal taxable wages (Box 1 on the W-2) is gross minus the pre-tax items the federal income tax system recognizes: traditional 401(k), HSA, Section 125 health and dental and vision premiums, FSA, dependent care FSA, commuter, qualified parking. Social Security wages (Box 3) is gross minus Section 125 health, HSA, FSA, commuter — but not minus 401(k). And it’s capped at the 2026 wage base of $176,100; once you hit the cap, OASDI stops withholding for the rest of the year. Medicare wages (Box 5) is the same as Social Security wages but with no cap.
Here’s a worked example that makes it less abstract. Take a San Diego software engineer named — let’s call her Priya — earning $217,840 in 2026. She maxes her 401(k) at $23,500, contributes $4,400 to an HSA via payroll, and elects a $3,200 healthcare FSA. Her pre-tax for federal purposes is $31,100, so her Box 1 lands at $186,740. Her pre-tax for FICA is just $7,600 (the 401(k) doesn’t count), so her Medicare wages are $210,240, and her Social Security wages are capped at $176,100. Three different numbers, one paystub, all correct. If somebody at her firm tries to “reconcile” Box 1 to Box 3, they will fail and conclude payroll is broken. It isn’t.
Withholdings — what you actually pay
Below the wage block comes the tax block. Federal Income Tax (often abbreviated FIT or FWT) is computed from IRS Publication 15-T using your W-4 elections plus the year-to-date method. Most modern payroll engines true up withholding each pay period rather than treating each check independently, which is why a bonus week doesn’t simply withhold 22% of the bonus — it can pull more or less depending on what’s been withheld so far. The W-4 calculator on this site reverse-engineers the same logic if you want to predict your check before payday.
OASDI is 6.2% of your Box 3 wages up to that $176,100 ceiling, so the absolute most an employer can withhold for you in 2026 is $10,918.20 (across all of your jobs combined, but each employer withholds independently, so two jobs can over-withhold and you reclaim the excess at filing). HI is 1.45% of Medicare wages with no cap. Once a single job’s YTD wages cross $200,000, the employer starts withholding an extra 0.9% Additional Medicare Tax under IRC § 3101(b)(2). The 0.9% threshold is $200,000 for everyone at the employer level, regardless of filing status — which is the source of an annoying paperwork problem for dual-income married-filing-jointly households whose combined wages cross $250,000 but no single job does. Your check won’t reflect the surtax, but you owe it on Form 8959 in April.
State income tax is its own world. New Hampshire taxes only interest and dividends. Washington taxes capital gains but not wages. New York City stacks 3.876% on top of New York State’s 6.85% top resident rate. Philadelphia takes 3.75% from city residents. Bits of Ohio, Indiana, Kentucky, Maryland, Michigan, and Alabama-Birmingham have local wage taxes. California, New York, New Jersey, Washington, Massachusetts, Oregon, Colorado, Connecticut, and Rhode Island withhold for state paid family and medical leave or short-term disability programs — small numbers individually but they add up. Hawaii and Puerto Rico run their own TDI. Alaska, New Jersey, and Pennsylvania take a small employee SUI contribution where most states don’t.
Post-tax deductions: the rest of the stub
Anything below the tax block comes out after the engine has calculated and withheld. Roth 401(k) contributions live here. So do voluntary supplemental life insurance, accident insurance, hospital indemnity, pet insurance, the ESPP withholding that sits in escrow until the purchase date, charitable matching contributions, union dues, and the part of your long-term disability premium your employer set up as post-tax so the eventual benefit is non-taxable. Wage garnishments — child support, an IRS levy under IRC § 6331, an administrative student loan garnishment under the HEA — also sit here, capped by the federal Consumer Credit Protection Act at 25% of disposable earnings (50% for child support if you support a second family, 60% if you don’t, plus 5% for arrearages older than 12 weeks).
Employer contributions and imputed income (the part that doesn’t hit your bank)
A good stub also shows what the employer paid about you that doesn’t affect your take-home but does affect your total compensation: the employer 401(k) match, the employer HSA contribution, employer share of health premiums, the employer half of FICA (which is a real cost on you — in self-employment, you’d pay both halves), FUTA, SUTA in most states. There may also be imputed-income lines for the part of group-term life over $50,000 of coverage, domestic-partner benefits where the partner isn’t a federal dependent, and any other fringe benefit that’s taxable to you under IRC § 132 but didn’t come with a cash payment.
Net pay and direct deposit
Net pay equals gross minus pre-tax deductions, minus taxes, minus post-tax deductions. That should match the deposit (or split deposits) to the dollar. If your bank shows something different, check that there isn’t a held check, a same-day re-issuance, or a deposit reversal pending. Banks settle ACH on a one-business-day delay for standard NACHA, same-day for ACH same-day windows; a Friday pay date can land Monday morning if the employer ran payroll on the second window.
Year-to-date is where the truth lives
Every current-period number on the stub has a YTD twin. Once a quarter, take five minutes with the last stub of the quarter and check: (a) YTD gross plus this check’s gross equals the new YTD; (b) YTD 401(k) is on track to the $23,500 limit, especially if you changed jobs mid-year; (c) YTD Social Security wages are approaching $176,100 but haven’t overshot; (d) YTD federal withholding annualized lands within a few hundred dollars of your projected liability. If the projection is off by more than $1,500 in either direction, adjust the W-4 now, not in December. Last December’s correction is January’s problem.
Two jobs in one year (the most common failure mode I see)
Each employer withholds as if it were your only job. Each employer assumes you take the standard deduction once. Each employer’s withholding engine starts the year fresh and walks you up the 10% bracket from dollar one. Result: when both jobs stack on the same W-2, you’ve been under-withheld by something between a few hundred and several thousand dollars depending on income and timing. The fix is either Step 2(c) (Multiple jobs) on both W-4s, or an extra dollar amount on Step 4(c), or quarterly estimated payments via Form 1040-ES (more on that in our quarterly estimated tax guide). The 401(k) catch is subtler: both employers will let you defer up to $23,500 because they don’t see each other’s YTD. If you contributed $15,000 at Job A and $13,000 at Job B, you’ve over-deferred by $4,500 and you’ll need a corrective distribution from one of the plans by April 15 of the following year.
The mistakes I keep finding
A short, opinionated list, in rough order of frequency at our firm last spring. State tax getting withheld for the wrong state for two to three pay periods after a remote move — employees almost always remember to change their address with HR; payroll engines almost always lag two cycles. FICA still being withheld at the old company after a parent-company restructure where the entity number changed mid-year, which generates a refund claim via Form 843 because the new entity is required to start over at the OASDI cap. HSA family contributions doubling when both spouses are contributing through separate employers and one of them flips to a non-HDHP mid-year. The two-job 401(k) over-deferral above. Pre-tax health premium showing as post-tax after a benefits enrollment outside open enrollment without a qualifying event under Treasury Reg 1.125-4 — this one’s usually permanent until next open enrollment. And bonuses withheld at the flat 22% supplemental rate when the employee is in the 32%+ bracket, which doesn’t show up as a problem until the April return.
FAQs
What is the difference between Box 1 and gross on my W-2?
Box 1 is gross minus your federally-tax-exempt pre-tax items — traditional 401(k), HSA, Section 125 health and FSA, commuter, qualified parking. It is not the same as the YTD gross on your December stub. If you’re trying to reconcile, the difference should equal your total pre-tax deductions for the year.
Why is my Social Security tax so much higher than my Medicare tax?
Social Security is 6.2%, Medicare is 1.45%. That’s already a 4.27x ratio before you factor in anything else. They’re separate programs with separate statutes.
Can my employer change my withholding without my permission?
Only if the IRS sends a lock-in letter under Treasury Reg 31.3402(f)(2)-1(g), a court orders a garnishment, or a state tax authority sends an equivalent notice. The employer cannot unilaterally raise withholding because they think you’ll owe.
Should I get a paper stub or just look at the portal?
State law controls. About half of US states require either a printed stub or an electronic stub the employee can print and that’s accessible at the time of payment. Texas and Tennessee are notable exceptions with no general stub requirement. I’d save twelve months at minimum — portals sometimes purge older data when an employer changes payroll providers.
Why doesn’t my net match the calculator?
Usually one of three things: a pre-tax line you didn’t enter in the calculator, a state-specific tax (SDI, PFML, local) the calculator doesn’t model, or supplemental withholding on a bonus that paycheck. See our methodology page for what we explicitly include and exclude.